Choices:
response_1 = "Satisfied with leap second"
response_2 = "No leap second"
response_3 = "Another preference (see comments)"
response_4 = "No opinion"
Date=08_July_2011
Family Name = Woltz
First Name = Lawrence
Institute = NASA
Country = USA
Field of activity = Satellite precipitation measurement
Response = response_1
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Date=08_July_2011
Family Name = van Schellen
First Name = Remco
Institute = Omroep Zeeland
Country = the Netherlands
Field of activity = Media
Response = response_1
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Date=08_July_2011
Family Name = Savoie
First Name = Denis
Institute = SYRTE-Observatory of Paris
Country = France
Field of activity = Astronomy-Astrophysics
Response = response_1
The redefinition of UTC will cause serious difficulties for fans of sundials. The converion of solar time in standard time will be even more complicated to explain to the public and students ! The calculation of analemma (directly indicating Universal Time by integrating the equation of time and the longitude) with will become problematic. Sundials are nothing in front of the lobby GPS; but their role in teaching astronomy is very important
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Date=08_July_2011
Family Name = Marmet
First Name = Louis
Institute = NRC Canada
Country = Canada
Field of activity = Time-laboratory
Response = response_1
The time scale TAI is already implemented for applications where a leap second would be a problem. I consider that a change of the definition of UTC will reduce the credibility of our institution (time standards community) in the eye of the public. Seriously affected will be the users who use the position of the sun. A redefinition of UTC will change the calendar date of these events and have serious social impacts once it becomes known to the public. There is not enough room here to bring more arguments...
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Date=08_July_2011
Family Name = Olsson
First Name = Sten
Institute = Lockheed Martin Corporation
Country = USA
Field of activity = Air Traffic Control
Response = response_1
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Date=08_July_2011
Family Name = Tang
First Name = Jingshi
Institute = Astronomy department, Nanjing University
Country = China
Field of activity = Astronomy-Astrophysics Celestial-mechanics Geodesy
Response = response_1
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Date=08_July_2011
Family Name = Cooper Jr.
First Name = Peter
Institute = None
Country = United States
Field of activity = Hobbiest that finds time interesting
Response = response_1
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Date=08_July_2011
Family Name = Gambis
First Name = Perceval
Institute = THALES
Country = France
Field of activity = Air Traffic Control
Response = response_2
In the field of Civil Air Navigation, UTC time is the reference.
We don't really care about TAI.
Leap seconds have always been an issue and sometimes a 1 second jump in the clocks can cause majors problems in our complex air traffic control systems and subsystems.
Getting rid of the leap seconds is preferable.
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Date=08_July_2011
Family Name = GONZALEZ
First Name = Hervé
Institute = Airbus Operations SAS
Country = France
Field of activity = Aeronautics
Response = response_1
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Date=08_July_2011
Family Name = Williams
First Name = David
Institute = Fidelity Bank
Country = USA
Field of activity = Telecommunication Information Technology
Response = response_1
Civil time reckoning has always been tied with the Earth’s rotation. Leap seconds are small enough that few people are inconvenienced and frequent enough that there are tested procedures on how to deal with them. Leap minutes or leap hours would be very disruptive. To drop the relationship with Earth’s rotation is to not deal with the issue and to kick the can down the road for someone else to deal with at a later time.
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Date=08_July_2011
Family Name = Enfinger
First Name = Eugene Bryan
Institute = Enfinger & Assoc., LLC
Country = USA
Field of activity = Astronomy-Astrophysics Celestial-mechanics Geodesy
Response = response_1
LEAVE THE CURRENT SYSTEM AS IS!!!!!!
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Date=08_July_2011
Family Name = Finch
First Name = Tony
Institute = Univ. of Cambridge Computing Service
Country = England
Field of activity = Telecommunication
Response = response_2
If we are to continue leap seconds, they will be much more easy to handle if they are announced several years in advance, such that leap second tables can be distributed as part of a computer system's software.
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Date=08_July_2011
Family Name = Smith
First Name = Eric
Institute = Total Spectrum Software
Country = Canada
Field of activity = Computer software
Response = response_3
I am generally satisfied with the current definition of UTC which includes leap seconds. However, I think it would be useful for leap seconds to be scheduled further in advance (for example several years, rather than 6 months). This would allow makers of computer systems to more readily schedule and prepare for leap seconds. This advantage would, I think, outweigh the difficulties in keeping DUT1 within 1 second over such a long period -- particularly if the alternative is to allow DUT1 to grow without bound!
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Date=08_July_2011
Family Name = Hall
First Name = Shannon
Institute = JHU/APL
Country = USA
Field of activity = Astronomy-Astrophysics Geophysics
Response = response_1
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Date=08_July_2011
Family Name = Seaman
First Name = Rob
Institute = National Optical Astronomy Observatory
Country = USA
Field of activity = Astronomy-Astrophysics
Response = response_1
I would support lengthening the forecast interval immediately to whatever value permits remaining within the 0.9s DUT1 limit - note that no change would be required to TF-460 to do this. The state of the art of EOP forecasts has improved dramatically since 1972 and we should benefit from that. I might additionally consider supporting the relaxation of the 0.9s limit to later permit lengthening the forecast interval further. Care should be taken with planning for any change to UTC. Due diligence has not been met by the current ITU-R process.
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Date=08_July_2011
Family Name = Vince
First Name = Peter
Institute = BBC Television
Country = United Kingdom
Field of activity = Broadcast radio and television
Response = response_2
UTC currently gives an accurate indication of the Earth's orientation - something most people have no interest in, particularly to the degree of accuracy achieved. Most people assume noon (12:00) to be when the sun is at its highest, but with the analemma effect, and especially daylight savings time, that is certainly not true.
Modern broadcasting and communication equipment needs an accurately synchronised reference, so variable frequencies tracking the Earth's rotation is not an option. With 24-hour broadcasting of mainly pre-recorded programmes, it is essential for professional continuity that the duration of the programme is known, and changing the clock time during the transmission of a programme negates this accuracy.
Leap-seconds were a good idea in 1972 when people just had a few inaccurate analogue clocks, but now so much equipment has a clock, it is a nightmare to correct it all. There is also a cost penalty to do this, for the time and effort of the staff involved, and the confusion, if not danger, of them not being corrected and synchronised.
I believe daylight-saving time should also be abolished, but that is another argument. At least let us take this opportunity to simplify time-keeping for the majority. There will be a cost penalty for the astronomers, but that is nothing to the cost currently incurred by everyone else. They already have to compensate for sidereal time and polar wobble - a slightly larger DUT-1 should be a very minor change.
But please ensure DUT-1 *IS* available to everyone, including modifying the LF radio time-signal data formats.
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Date=08_July_2011
Family Name = Müller
First Name = Ulrich
Institute = Institut für Kernphysik, Univ. Mainz
Country = Germany
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=08_July_2011
Family Name = Theodosiou
First Name = Georgios
Institute = None
Country = France
Field of activity = jobless
Response = response_3
Redefinition, or better, new name, for example: Universal Civil Time (UCT) with its own unit, UCT second, defined as 1/86400 of mean solar day, under condition |UT1-UCT| < 1 sec.
Due to earth slowing and variation in LOD some slight increase (10-20 nanosec) every 19 years (metonian cycle, largest periodic element in LOD) will be needful in UCTsec. It's possible this increase be allocated each year or even each day.
Atomic time and its second will remain time scale for scientific and technical purposes, GPS etc, and UT1 and its second for astronomical purposes.
With regards
Georgios Theodosiou
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Date=08_July_2011
Family Name = Sokolov
First Name = Michael
Institute = Citizen of the Universe
Country = Republic of New Poseidia
Field of activity = moral and political philosophy
Response = response_1
For thousands of years the effective definition of a day has been the mean solar day. Hours, minutes and seconds are merely subdivisions of the millennia-old concept of the day. In other words, for thousands and thousands of years the definition of "day" and the time of day has been given by Mother Nature, i.e., by the Sun in the sky. What the outrageous ITU proposal is effectively asking us to do is to give up our trust in Mother Nature in the matters of time of day and to vest our trust instead in the racks of strange equipment operated by a bunch of guys in lab coats.
Universal Time means mean solar time. Anyone who attempts to redefine UTC as something that isn't Universal Time should be arrested and prosecuted for treason against nature / crimes against humanity.
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Date=08_July_2011
Family Name = DENIEL
First Name = Laurent
Institute = THALES
Country = France
Field of activity = Telecommunication
Response = response_2
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Date=08_July_2011
Family Name = Griesbach
First Name = Jacob
Institute = Analytical Graphics, Inc.
Country = USA
Field of activity = Astronomy-Astrophysics
Response = response_1
I believe it's important that UTC retain its celestial meaning. The rather infrequent use of leap seconds is only a light burden to maintain this synchronicity.
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Date=08_July_2011
Family Name = Hujsak
First Name = Richard
Institute = Analytic Graphics, Inc
Country = United States
Field of activity = Celestial-mechanics orbit determination and prediction
Response = response_1
There are too many software systems with the current definitions embedded. The costs of changing that many systems for a frivolous change in definition is too great to be worth while. The danger is some systems would convert to the new definition, while others would not. And that mismatch can have expensive consequences. In the words of a famous procrastinator "If it ain't broke, don't fix it."
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Date=08_July_2011
Family Name = Viceré
First Name = Andrea
Institute = Università di Urbino
Country = ITALY
Field of activity = Astronomy-Astrophysics Gravitational Waves
Response = response_2
In my field, we rely on GPS counts as a uniformly increasing timescale. UTC would replace it very well and serve as a reference solution.
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Date=08_July_2011
Family Name = Gupta
First Name = Sanjeev
Institute = DCS1
Country = Singapore
Field of activity = Telecommunication
Response = response_1
I prefer that UTC closely follow a smoothed UT1.
I would accept an increase in the allowed value of DUT1, if it would help in long-range predictions of leap seconds.
--
Sanjeev
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Date=08_July_2011
Family Name = Candey
First Name = Robert
Institute = NASA
Country = USA
Field of activity = Space-sciences
Response = response_2
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Date=08_July_2011
Family Name = West
First Name = Michael
Institute = Geophys. Inst., Univ. Alaska Fairbanks
Country = United States
Field of activity = Geophysics
Response = response_2
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Date=08_July_2011
Family Name = Meagher
First Name = Kevin
Institute = University of Maryland
Country = USA
Field of activity = Astronomy-Astrophysics
Response = response_1
I think that is important for astronomy to keep UT and UTC as close together as possible, As far as I knwo, all of the problems associated with leap seconds are due do substandard software. These problems could be mitigated by standard software libraries to handle leap seconds.
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Date=08_July_2011
Family Name = Dewar
First Name = Duncan
Institute = none
Country = Scotland
Field of activity = Astronomy-Astrophysics Telecommunication
Response = response_1
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Date=08_July_2011
Family Name = Clark
First Name = Richard
Institute = National Solar Observatory
Country = USA
Field of activity = Astronomy-Astrophysics
Response = response_1
There is already TAI and the GPS timescale. Why do we need STILL ANOTHER conatant uniform timescale?
Keep UTC as it is.
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Date=08_July_2011
Family Name = Finkleman
First Name = David
Institute = CSSI and ISO TC20/SC14
Country = USA
Field of activity = Astronomy-Astrophysics Space-sciences
Response = response_1
I appreciate that we are referenced, but this matter is scientific and concrete, not abstract or a matter of opinion. I ask why opinion is important and whether the results of this survey will be cited to support or claim any collective consensus. Also, you might cite our American Scientist Magazine article instead of the AIAA paper. The former is more widely accessible at no cost and captures the issues more concisely.
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Date=08_July_2011
Family Name = Kenworthy
First Name = Matthew
Institute = Leiden Observatory
Country = The Netherlands
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=08_July_2011
Family Name = Wyatt
First Name = Wiliam
Institute = Smithsonian Astrophysical Observatory
Country = USA
Field of activity = Astronomy-Astrophysics
Response = response_1
The worst case would be for UTC to be redefined as proposed, i.e. without
a name change to distinguish it from earlier UTC.
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Date=08_July_2011
Family Name = Hochschild
First Name = Peter
Institute = Google
Country = United States
Field of activity = Large Scale Distributed Computing
Response = response_2
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Date=08_July_2011
Family Name = Laney
First Name = C. David
Institute = Brigham Young University
Country = United States
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=08_July_2011
Family Name = Buinoud
First Name = Maxime
Institute = French Navy
Country = France
Field of activity = Studies
Response = response_1
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Date=08_July_2011
Family Name = Scott
First Name = Mike
Institute = Vercet LLC
Country = USA
Field of activity = Design of Geophysical Recording Systems
Response = response_2
Je voudrais un système qui apporte des corrections au plus une fois tous les 10 ans, et donne un préavis minimum de 1 an de tout changement, merci de me donner l'opportunité d'avoir mon mot à dire, la nature ce qui concerne Mike
I would like a system that makes corrections no more than once every 10 years, and gives a minimum of 1 year’s notice of any changes, thank you for giving me the opportunity of having my say, kind regards Mike
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Date=09_July_2011
Family Name = Townsend
First Name = Gregg
Institute = University of Arizona (retired)
Country = United States
Field of activity = Telecommunication Computer Science
Response = response_2
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Date=09_July_2011
Family Name = Osvaldo
First Name = Osvaldo Fernández
Institute = Ex profesor of The Patagonia University
Country = Argentina
Field of activity = Astronomy-Astrophysics Geodesy
Response = response_1
I enjoy making astronomical measures of latitude and longitude by theodolite and chronograph. I need DUT1.
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Date=09_July_2011
Family Name = Pfyffer
First Name = Gregor
Institute = Royal Observatory of Belgium
Country = Belgium
Field of activity = Geodesy Geophysics
Response = response_1
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Date=09_July_2011
Family Name = Hansen
First Name = Ask
Institute = The NTP Pool project
Country = USA
Field of activity = Time synchronization; computer systems
Response = response_2
I operate a system providing time services for tens of millions of computers via about 2000 volunteered ntp servers.
Analyzing the performance of the time servers during the 2008/2009 leap second showed a worrying percentage of (otherwise well configured and well maintained) systems being a second out of sync with everyone else for hours and in some cases even days!
For computer system operations at both small and late scale the leap second comes at a great cost. For less time critical systems it "just" means that any logs or any other timed informatio around the leap second are unusable or at best suspect.
For time critical systems to cost is shutting down the system around the leap second or if that isn't possible then great and difficult engineering around it.
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Date=09_July_2011
Family Name = Barnes
First Name = Howard
Institute = Georgi Dobrovolski Solar Observatory
Country = New Zealand
Field of activity = Astronomy-Astrophysics
Response = response_1
Perhaps, a "leap minute" once a century might do. That would be better than this silly idea of a "leap hour".
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Date=09_July_2011
Family Name = Wilkinson
First Name = James
Institute = Google
Country = Australia
Field of activity = Internet
Response = response_1
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Date=09_July_2011
Family Name = Withers
First Name = Laurence
Institute = Güralp Systems Ltd
Country = United Kingdom
Field of activity = Geophysics
Response = response_2
For seismology, which my company generally focuses on, and other areas of geophysics, we must use a global time reference so that data from geographically distant measurement stations can be correlated. Furthermore, this time reference must be constant (i.e. the definition of one second must not vary), as otherwise any frequency-based calculations would be inaccurate.
Unfortunately, seismologists universally use UTC and not TAI for this time source. As a software engineer dealing with acquisition, transmission and processing systems I know from my own experience and from observing other software in the field that leap seconds are an area of huge complexity, often doubling the amount of code required for any timestamp-related task. Furthermore, each leap second occurrence leads to a raft of system failures across all manufacturers.
Changing the definition of UTC to be TAI with a constant offset would greatly simplify the task of writing and maintaining software and remove an area of significant concern.
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Date=09_July_2011
Family Name = Trueblood
First Name = Mark
Institute = National Optical Astronomy Observatory
Country = United States of America
Field of activity = Astronomy-Astrophysics
Response = response_1
Can you imagine the havoc created by this proposal to make UTC an atomic time? The civil time of
day MUST be tied to the Earth's rotation. This rotation is gradually slowing due to tidal friction with
the Moon. Therefore, we need to continue to introduce leap seconds into the time to keep our
clocks in synch with where the Sun is in the sky. Over a period of centuries, the proposed change to
an atomic time would make us rise at odd hours of the day, and make it impossible to point
telescopes accurately. This proposal is sheer nonsense.
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Date=09_July_2011
Family Name = McCartney
First Name = Craig
Institute = On-Site Training International
Country = USA
Field of activity = Telecommunication Time-laboratory
Response = response_1
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Date=09_July_2011
Family Name = Kulda
First Name = Tomas
Institute = Charity
Country = Czech Republic
Field of activity = computer programmer
Response = response_2
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Date=10_July_2011
Family Name = Deines
First Name = Steve
Institute = Donatech Corporation, Inc.
Country = USA
Field of activity = Navigation
Response = response_1
Until the timekeeping community understands Universal Time, it is best to keep the status quo with UTC. Tidal friction is a torque that causes a quadratic deceleration of Earth's orientation. The simplest model of tidal friction is a constant deceleration that will cause the angular velocity (Earth's inertial spin) to decrease linearly and its angular displacement to lag in a quadratic curve. The current definition of UT1 comes from the formula from Capitaine et al, and that formula converts Earth orientation angle into UT1. Since the formula was first published in 1986, the epoch associated with the data is circa 1980, maybe 1981. The last two leap seconds roughly fit a quadratic curve after that epoch, which remarkably fits the tidal friction curve. Christodoulidis et al (1988) obtained -5.98±.22E-22 rad/sec2 from analyzing 17 artificial satellites. From the fossil record, I obtained a value of -5.99±1.77E-22 rad/sec2 was obtained from 17 studies involving 44 fossils.
It is a straightforward statistical test to show that the last two leap seconds do not come from the same population of leap seconds between 1972 and 1998. The Dec 2005 leap second was 11.96 st. dev. off and the Dec 2008 leap second was 3.96 s.d. off. Both fail the 99.9% acceptance test.
Knowing that result, the divergence between TAI and UT1 between 1958 and 1998 is nearly linear. If you review the processing of that time, (See Markowitz 1968 in Telescopes) the operational epoch was advanced every day when PZT data were taken and processed. Moving the epoch would hide tidal friction under the noise in the measurements. Now, VLBI gets Earth orientation data very precisely. The operational epoch is now frozen (embedded in Capitaine et al formula), and tidal friction is now revealed in divergence between UT1 and TAI. There is no uniform divergence anymore. In a few decades, tidal friction will invalidate the Capitaine et al formula that obtains UT1, because tidal friction was never incorporated into the derivation.
I firmly believe that the timekeeping community should postpone the vote until it thoroughly reviews the effects of tidal friction, which is not incorporated into the current prediction models for the divergence between UT and TAI, and definitely not in the Capitaine et al formula that defines UT1.
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Date=10_July_2011
Family Name = Bertou
First Name = Xavier
Institute = Centro Atómico Bariloche
Country = Argentina
Field of activity = Astronomy-Astrophysics
Response = response_2
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Date=10_July_2011
Family Name = Goodwin
First Name = Julien
Institute = -
Country = Australia
Field of activity = Telecommunication
Response = response_1
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Date=10_July_2011
Family Name = Lynch-Aird
First Name = Nicolas
Institute = Independent
Country = UK
Field of activity = Telecommunication
Response = response_1
Leap seconds should be retained as the ongoing mechanism for maintaining UTC close to UT1. Allowing UTC to drift away from UT1 will necessitate larger corrections to be made at some unspecified point in the future which will be far more disruptive than the current system of introducing leap seconds.
It would be of greater benefit to extend the time code transmission standards in such a way as to enable automated systems to be able to detect an upcoming leap second in advance of the event. Assuming that the transmission of DUT1 is retained then this only requires one extra bit of information - the sign of the leap second can be determined from the sign of the preceeding value of DUT1. It would be beneficial also to include additional flags in the transmitted data to indicate an upcoming change in the transmitted value of DUT1.
Finally the time code standard should be made freely and publicly available. In this way equipment manufacturers will be more readily able to develop systems that can respond in a wholly automated manner to changes in DUT1 and the introduction of leap seconds.
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Date=10_July_2011
Family Name = Scott-Thoennes
First Name = Yitzchak
Institute = Shiftboard
Country = US
Field of activity = Telecommunication
Response = response_1
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Date=10_July_2011
Family Name = Kapounek
First Name = Petr
Institute = comerce sphere
Country = Czech Republic
Field of activity = Telecommunication
Response = response_1
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Date=10_July_2011
Family Name = Verhaege
First Name = Christophe
Institute = Laboratoire de Météorolige Physique
Country = France
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=11_July_2011
Family Name = Lim
First Name = Peter
Institute = Nil
Country = Singapore
Field of activity = NIL
Response = response_2
NIL.
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Date=11_July_2011
Family Name = Siddiqui
First Name = Hassan
Institute = ESA/ESAC
Country = Spain
Field of activity = Astronomy-Astrophysics
Response = response_2
Having a time scale that is discontinuous causes a lot of problems with writing and maintaining software for processing non-ground-based astronomical missions, and in particular the link to the spacecraft and the ground segment. It would help immensely if UTC is redefined such that it represents terrestrial time in as simple a way as possible.
Of course, a counter-argument for my request is to simply use TAI right now instead of UTC - if in the future the difference would be a constant. This is in fact my preference. However, a lot of ground based activities are heavily intertwined to UTC, it is best to work on making that system simpler.
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Date=11_July_2011
Family Name = Herrero
First Name = Javier
Institute = HV Sistemas S.L.
Country = Spain
Field of activity = Space-sciences
Response = response_2
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Date=11_July_2011
Family Name = Meyer
First Name = François
Institute = Observatoire de Besançon
Country = France
Field of activity = Time-laboratory
Response = response_1
It seems that addressing the main engineering concerns
generated by leap seconds, could be greatly simplified
by enhancing the accessibility and timespan of the leap
second table :
such a table, would list not only past leap seconds but
also scheduled leap seconds for the next 10 years (instead
of the 6 month notice that is in use today), and should be
made widely available.
Involving only minimal changes, this would be a good, conservative
compromise, both preserving the UT feature of UTC (which should not be
thrown away lightly in my opinion) and smoothing its
engineering drawbacks, at least for the next centuries
as long as the average frequency of leap seconds remains
below one per month.
--
F. Meyer
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Date=11_July_2011
Family Name = Ochsenbein
First Name = Francois
Institute = CDS, Obs. Strasbourg
Country = France
Field of activity = Astronomy-Astrophysics
Response = response_2
Some adjustment would however be necessary in the future to avoid a too large difference (>15min? >1hr?) with Earth rotation but there will be plenty of time to converge on a concensus :-)
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Date=11_July_2011
Family Name = vallado
First Name = david
Institute = center for space standards and innovatio
Country = usa
Field of activity = Celestial-mechanics
Response = response_1
There are a great number of systems that include processing for leap seconds. Adding the leap seconds mainatians uniformity between the actual earth rotation and time systems. I see no need to change that.
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Date=11_July_2011
Family Name = Bernstein
First Name = Gary
Institute = University of Pennsylvania
Country = US
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=11_July_2011
Family Name = Francis
First Name = Gribbin
Institute = Isaac Newton Group
Country = Spain
Field of activity = Astronomy-Astrophysics
Response = response_1
At the Isaac Newton Group we use UTC (from atomic clock) as input to the
the Telescope Control System. We receive notifications of leap seconds via
the IERS bulletin. Our systems can be programmed such that the leap second
is introduced automatically: this involves setting hardware switches on the
clocks to specify when the leap second is to be introduced and updating control
system parameter to say when it is to be expected.
Since the clock is autonomous we have also omitted programming the leap second
(e.g. on 31-Dec-2011) and introduced manually it later (when it's not a holiday).
So we can cope fine with leap seconds. Omitting leap seconds will create some
more work (although with our independent clocks we could avoid this).
Overall I think the argument is about whether UTC should be related to the sun.
Since all of us still live on the planet (earth) it make sense to continue the
current regime.
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Date=11_July_2011
Family Name = Swaters
First Name = Robert
Institute = NOAO
Country = USA
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=11_July_2011
Family Name = Murray
First Name = Stephen
Institute = Johns Hopkins University
Country = USA
Field of activity = Astronomy-Astrophysics
Response = response_1
I do not think a change in the current definition of UTC is good for astronomy and celestial navigation activities. There is a great deal invested in the current definition and the software that uses it and any change would likely lead to errors for many years as the transition would need to propagate across many systems and users..
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Date=11_July_2011
Family Name = Main
First Name = Andrew
Institute = no affiliation
Country = United Kingdom
Field of activity = software engineering
Response = response_3
I have no strong opinion on whether the main broadcast time scale, or the basis of civil time, should continue to track UT1. However, I have opinions about other aspects of the process.
Any time scale that does not closely track UT1 would not be a form of UT, and should not have a UT-related name. Specifically, the time scale resulting from initially synchronising with present UTC and then not applying leap seconds would not be a form of UT, and so should not be called "UTC". The name "International Time" with initialism "TI" has been proposed for such a time scale, and I would find that entirely satisfactory. It should, of course, be clearly defined whether proleptic TI matches UTC over UTC's prior period of operation or remains a constant offset from TAI; I think the latter is more manageable.
Although many users would prefer a leap-second-less time scale, and many more can at least accept one, it is not feasible to force such a time scale on all present users of UTC. Some would continue to desire a time scale behaving like the present form of UTC, with leap seconds. If such a scale is not readily available then it will be necessary to invent one, but local reinvention repeated by many users would cause a proliferation of badly-managed not-quite-compatible time scales. Thus it would remain useful for IERS to issue canonical leap second decisions for such users, defining a standard time scale that would continue to behave as the current UTC does. This time scale should probably be named "UTC".
The decision about the time scale that is used in broadcast dissemination of time should be divorced from other questions about UTC. The broadcast time scale may sensibly be UTC as presently defined, TAI plus an offset (TI as described above), or plain TAI. Whichever is chosen as the primary broadcast time scale, broadcasts should where possible carry the parameters needed to convert between UTC-with-leap-seconds and TI/TAI. Where those parameters are readily available, the exact choice of primary time scale becomes much less significant.
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Date=11_July_2011
Family Name = Flanders
First Name = Tony
Institute = Sky & Telescope
Country = USA
Field of activity = Astronomy-Astrophysics
Response = response_1
Presumably, civil time would continue to be tied to UTC. This would cause sunrise and sunset times to become unpredictable, which seems like a very bad thing in the long run. Julius Caesar tried adopting a simple, uniform time scale in his eponymous calendar; it turned out to be a short-sighted solution.
Until the day when we all live in underground enclosures, as foreseen by many science-fiction writers, let's not allow the convenience of a few technologists to take precedence over the Sun!
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Date=11_July_2011
Family Name = Paget
First Name = James
Institute = The Aerospace Corporation
Country = USA
Field of activity = Astronomy-Astrophysics Celestial-mechanics Space-sciences
Response = response_1
Please be sure to make UT1 or UT1C available (such as by radio signals) if you decide to allow UTC to drift more than 1 second from UT1.
Please consider renaming UTC if leap seconds are no longer included.
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Date=11_July_2011
Family Name = Martin-Mur
First Name = Tomas
Institute = JPL
Country = USA
Field of activity = Celestial-mechanics
Response = response_2
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Date=11_July_2011
Family Name = Greve
First Name = Tora
Institute = Tycho Brahe Observatory
Country = Sweden
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=11_July_2011
Family Name = Lee
First Name = Steven
Institute = AAO
Country = Australia
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=11_July_2011
Family Name = Dicker
First Name = Simon
Institute = Upenn
Country = USA
Field of activity = Astronomy-Astrophysics
Response = response_2
5 years may be too soon to switch.
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Date=12_July_2011
Family Name = Laidler
First Name = Victoria
Institute = Space Telescope Science Institute
Country = USA
Field of activity = Astronomy-Astrophysics
Response = response_1
I am primarily a developer and maintainer of astronomical software.
Although it is somewhat annoying to have to update some software to account for the latest leap second, it would be far more annoying to have to use "a separate access to UT1, such as through the publication of DUT1 by other means" and implement support for both kinds of time.
From my perspective, the current system works. It is not broken. Let's not fix it.
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Date=12_July_2011
Family Name = Fulco
First Name = Charles
Institute = Port Chester Middle School
Country = USA
Field of activity = Astronomy-Astrophysics Space-sciences
Response = response_1
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Date=12_July_2011
Family Name = Kamp
First Name = Poul-Henning
Institute = The FreeBSD Project
Country = Denmark
Field of activity = Telecommunication Operating System Design & Implementation
Response = response_3
The main operational problem with leap seconds is the very short warning.
6-10 months is not nearly enough for operating systems to propagate this information to all installed copies.
If leap seconds were announced 10-20 years in advance, tables could be distributed with operating systems and their updates, and computer systems consequently could be trusted to always have up to date tables when leap seconds strikes.
If this is not a possible compromise, leap seconds should be abolished.
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Date=12_July_2011
Family Name = Tricarico
First Name = Pasquale
Institute = Planetary Science Institute
Country = USA
Field of activity = Astronomy-Astrophysics Celestial-mechanics Space-sciences
Response = response_1
I think that UTC should stay as it is. If you want to create another timescale, like UTC but without leap seconds, go ahead, just call it something else than UTC. How difficult is that?
That said, scientific arguments should prevail over surveys and votes. If there is a strong scientific argument for changing UTC, so be it. But it seems to me that this is not the case, and as you state, a UTC without leap second would be of lesser value than the current UTC definition, so really I don't see the point of it.
Regards.
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Date=12_July_2011
Family Name = CHENAL
First Name = JONATHAN
Institute = INSTITUT GEOGRAPHIQUE NATIONAL
Country = FRANCE
Field of activity = Geodesy
Response = response_1
Continuous timescales still exists, as TAI. In my opinion, it is important to have a basis for legal times (UTC) which follows solar times (UT1). If UTC is a source of problems because of its discontinuities, UTC should simply disappear et be replaced by TAI. UTC is useful precisely because of its discontinuities. A temporary solution could be to create a new timescale, continuous, in parallel to UTC, which would stay the basis of legal timescales. This new continuous timescale would be used for tests only, and could have a permanent entire offset with TAI, which could be the actual value of TAI-UTC. But my preference is to keep the actual definition of UTC, which includes leap second.
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Date=12_July_2011
Family Name = Tang
First Name = Jingshi
Institute = Astronomy department, Nanjing University
Country = China
Field of activity = Astronomy-Astrophysics Celestial-mechanics Geodesy
Response = response_1
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Date=12_July_2011
Family Name = Schittel
First Name = Christoph
Institute = Plusnet GmbH & Co. KG
Country = Germany
Field of activity = Telecommunication
Response = response_1
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Date=12_July_2011
Family Name = Schrama
First Name = Ernst
Institute = TU Delft
Country = The Netherlands
Field of activity = Geodesy Space-sciences
Response = response_1
Please do not change standards, we agreed once upon a time on a definition, textbooks spend text on this problem, etc, so why change that.
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Date=12_July_2011
Family Name = Thivillon
First Name = Alain
Institute = N/A
Country = France
Field of activity = Telecommunication
Response = response_1
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Date=12_July_2011
Family Name = Maisonobe
First Name = Luc
Institute = CS Communication & systèmes
Country = France
Field of activity = Celestial-mechanics
Response = response_1
Leap seconds are already well understood and well implemented in many space systems.
Systems that handle several time scales (say TAI and UTC) either already support leap seconds introduction in real time or have a constant TAI-UTC offset in a configuration file and need a restart a few days after the leap. Systems that handle only one time scale simply don't see anything and run seemlessly when leap seconds occur. So for ALL these systems, regardless of their implementation, leap seconds are clearly not a problem.
However, ALL these systems are based on assumption DUT1 remains small (less than 0.9s in the current setup). A few high precision systems track this value from IERS files, almost all systems do not track it and consider it to be 0. Removing the leap second would mean ALL systems should track DUT1 as the simplifying assumption would not hold anymore. This would imply modifying data handling, importing external data in operational systems that did not import anything beforehand, modifying ALL software layers to propagate this DUT1 down to the lower layers for frames transforms, revalidating EVERY space flight dynamics in the world. So for all systems except the very few high precision and costly ones that have already done this work, removing the leap second would in fact induce a lot of difficult work.
There are plenty of fixed time scales already available (TAI, GPS, Galileo ...) and only one time scale that is a convenient compromise between purely geometric TU1 and regular physics TAI, lets keep it.
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Date=12_July_2011
Family Name = DEFRAIGNE
First Name = PASCALE
Institute = ROYAL OBSERVATORY OF BELGIUM
Country = BELGIUM
Field of activity = Time-laboratory
Response = response_2
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Date=12_July_2011
Family Name = Street
First Name = Jim
Institute = N/A
Country = USA
Field of activity = Telecommunication
Response = response_2
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Date=12_July_2011
Family Name = poggi
First Name = jerome
Institute = -
Country = France
Field of activity = Governement
Response = response_1
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Date=12_July_2011
Family Name = Saers
First Name = Paul
Institute = private
Country = Sweden
Field of activity = Computing industry
Response = response_1
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Date=12_July_2011
Family Name = Aerts
First Name = Wim
Institute = ROB
Country = Belgium
Field of activity = Telecommunication Time-laboratory
Response = response_3
Why not introducing leap minutes instead of leap seconds?
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Date=12_July_2011
Family Name = Helk
First Name = Frank
Institute = -
Country = Germany
Field of activity = process computing
Response = response_1
If there's a need for another time refrence - like the proposed "UTC without leap seconds" or otherwise - it should be defined as a new entity and be distributed separately.
Redefinig a widely used standard would only lead to problems ... if anybody needs the new reference, he should use it on a "new service" base.
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Date=12_July_2011
Family Name = Widdas
First Name = Brian
Institute = n/a
Country = UK
Field of activity = Telecommunication
Response = response_1
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Date=12_July_2011
Family Name = Brouw
First Name = WN
Institute = Groningen University
Country = Netherlands
Field of activity = Astronomy-Astrophysics Celestial-mechanics
Response = response_1
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Date=12_July_2011 , 11h34
Family Name = West
First Name = Richard
Institute = University of Leicester
Country = UK
Field of activity = Astronomy-Astrophysics
Response = response_2
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Date=12_July_2011 , 11h34
Family Name = Clarke
First Name = Peter
Institute = Newcastle University
Country = United Kingdom
Field of activity = Geodesy Geophysics
Response = response_1
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Date=12_July_2011 , 11h51
Family Name = Mueller
First Name = Juergen
Institute = Institute of Geodesy, Univ. of Hannover
Country = Germany
Field of activity = Celestial-mechanics Geodesy
Response = response_1
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Date=12_July_2011 , 12h41
Family Name = Nothnagel
First Name = Axel
Institute = IGG, University of Bonn
Country = Germany
Field of activity = Geodesy
Response = response_1
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Date=12_July_2011 , 13h01
Family Name = Pardo
First Name = Jeff
Institute = SES
Country = US
Field of activity = Celestial-mechanics
Response = response_1
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Date=12_July_2011 , 13h57
Family Name = Ewell
First Name = Douglas
Institute = Individual
Country = USA
Field of activity = Software development
Response = response_1
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Date=12_July_2011 , 14h15
Family Name = Wallace
First Name = Patrick
Institute = RAL Space
Country = UK
Field of activity = Astronomy-Astrophysics observatory automation
Response = response_3
Leap seconds are a nuisance, and surprisingly difficult to deal with reliably in software. However, there are unknown numbers of applications in existence which, explicitly or implicitly, rely on the distributed time to be close to UT1. So the choice is between continuing to distribute an approximation to UT1 or accepting that problems will occur.
With the ubiquitous use of NTP, I believe there is now an opportunity to separate civil time from the high-precision time/frequency dissemination services. This would be done by providing UT1-based NTP servers, for dissemination of ordinary time-of-day and expressly intended for applications not requiring accuracies of better than 0.1s. We could call it GMT, which many countries still refer to in their laws. (The fact the the US law was changed not long ago to say UTC is regrettable but should not be allowed to influence the debate.)
The existing time/frequency dissemination services would by default distribute leapless UTC. As the difference between this and UT1 grows, developers of computer applications would become used to the idea that they had to make a choice - which they do now, in principle.
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Date=12_July_2011 , 14h16
Family Name = Jubier
First Name = Xavier
Institute = None
Country = France
Field of activity = Astronomy-Astrophysics
Response = response_1
I have nothing against a change. However, I would point out that each definition has its merit. So why change if it doesn't really bring anything or simplify computations.
As for predictions of eclipses in future years (especially within the next 100 years) the proposal to cease inserting leap seconds (that is, keeping UTC fixed with respect to TT) has significant merit – it will allow accurate UTC predictions to be issued many years before the event. Nevertheless it doesn't change anything since the difference between UT1 and UTC would henceforth be unconstrained!
At the same time, the current prediction methodology contains two ‘unknowns’ for future predictions. The conversion from TT to UTC, and the rotational position of the Earth (UT1-UTC). Of these, the effect of the uncertainty in prediction times resulting from the conversion from TT to UTC is an order of magnitude greater than the effects of the rotation of the Earth over the same time period. However if leap seconds are discontinued, the two uncertainties are reduced to just one – the rotational orientation of the Earth. And of the two uncertainties, this is the one that has the lesser impact on actual prediction times.
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Date=12_July_2011 , 14h16
Family Name = Ray
First Name = Jim
Institute = U.S. National Geodetic Survey
Country = USA
Field of activity = Geodesy
Response = response_1
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Date=12_July_2011 , 14h18
Family Name = Goerres
First Name = Barbara
Institute = Instiutut for Geodesy, University Bonn
Country = Germany
Field of activity = Geodesy
Response = response_1
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Date=12_July_2011 , 14h21
Family Name = Willmott
First Name = Paul
Institute = AMSAT-BDA
Country = Bermuda
Field of activity = Astrodynamics
Response = response_1
We have no wish to reprogram thousands of lines of complex astrodynamics code. Given that we will have to maintain the original UTC definition for our historical data, it will all be very confusing.
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Date=12_July_2011 , 14h28
Family Name = Schoene
First Name = Tilo
Institute = GFZ Potsdam
Country = Germany
Field of activity = Geodesy
Response = response_1
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Date=12_July_2011 , 14h29
Family Name = Grant
First Name = Mike
Institute = Plymouth Marine Laboratory
Country = UK
Field of activity = Remote Sensing (satellite and airborne)
Response = response_2
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Date=12_July_2011 , 14h45
Family Name = Newhal
First Name = X X (Skip)
Institute = Jet Propulsion Laboratory (Retired)
Country = USA
Field of activity = Astronomy-Astrophysics Celestial-mechanics Planetary Ephemerides
Response = response_1
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Date=12_July_2011 , 14h53
Family Name = Beyerle
First Name = Georg
Institute = GeoForschungsZentrum Potsdam
Country = Germany
Field of activity = Geodesy GNSS Remote Sensing
Response = response_2
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Date=12_July_2011 , 14h57
Family Name = Lennon
First Name = Christopher
Institute = MIT Lincoln Laboratory
Country = USA
Field of activity = Radar Systems
Response = response_1
GPS time exists as a free running clock alternative to UTC. One needs to maintain the list of leap seconds to go back an forth, but that is only a minor pain in the neck.
I have a mild preference that UTC maintain its connection with the rotation of the earth.
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Date=12_July_2011 , 15h02
Family Name = Kidger
First Name = Mark
Institute = ESA
Country = Spain
Field of activity = Astronomy-Astrophysics
Response = response_1
The current system has worked for years, why change it? Keep the day linked to the rotation of the Earth.
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Date=12_July_2011 , 15h05
Family Name = Svalgaard
First Name = Leif
Institute = Stanford University
Country = USA
Field of activity = Space-sciences
Response = response_2
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Date=12_July_2011 , 15h08
Family Name = Fani
First Name = Paolo
Institute = -
Country = Italy
Field of activity = Astronomy (amateur)
Response = response_1
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Date=12_July_2011 , 15h19
Family Name = Visser
First Name = Pieter
Institute = Delft University of Technology
Country = Netherlands
Field of activity = Celestial-mechanics Geodesy Geophysics Space-sciences
Response = response_1
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Date=12_July_2011 , 15h42
Family Name = Seidelmann
First Name = P. Kenneth
Institute = University of Virginia
Country = USA
Field of activity = Astronomy-Astrophysics Celestial-mechanics Space-sciences
Response = response_1
I think the definition of UTC should be considered by much wider scientific and administrative organizations than the ITU. The full impact of the change and its implications need to be considered.
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Date=12_July_2011 , 15h44
Family Name = HESTROFFER
First Name = Daniel
Institute = IMCCE
Country = France
Field of activity = Astronomy-Astrophysics Celestial-mechanics
Response = response_4
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Date=12_July_2011 , 15h47
Family Name = Mueller
First Name = Ivan
Institute = The Ohio State University
Country = USA
Field of activity = Geodesy Geophysics
Response = response_1
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Date=12_July_2011 , 16h11
Family Name = Dr. Federspiel
First Name = Martin
Institute = Planetarium Freiburg
Country = Germany
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=12_July_2011 , 16h20
Family Name = Hase
First Name = Hayo
Institute = Bundesamt für Kartographie und Geodäsie
Country = Germany
Field of activity = Astronomy-Astrophysics Geodesy
Response = response_1
Based on my personal experience: The existence of the leap second convinces common people to understand the need of geodetic VLBI and justify its expensive operation.
If the product "leap second" becomes officially superfluous, the current VLBI programmes are put in danger.
The importance of VLBI is not only based in the "leap second". But it is the easiest argument to communicate to politicians and administrators of financial resources.
Both cited articles mention "VLBI" only once and do not focus on the global VLBI infrastructure which is still contributing to the "leap second" determinations.
The number of arguments for pro and contra shows the need for both timescales:
- the atomic time scale
- the earth rotation time scale.
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Date=12_July_2011 , 17h19
Family Name = Martin
First Name = Thomas
Institute = Van Martin Systems, Inc.
Country = United States
Field of activity = Geodesy Space-sciences Precision satellite orbit determination
Response = response_1
UTC serves a very useful purpose. For those for whom UTC leap seconds present a problem, we already have TAI and GPS time which are uniformly increasing atomic time scales. With the advent of GNSS, anyone anywhere in the world has access to GPS time at very little cost. GLONASS, and I believe some SBAS systems, provide UTC. Additional systems coming on-line, including QZSS and Galileo, essentially also provide GPS time with extremely small offsets. Conversion algorithms between UTC and TAI or GPS border on trivial and are readily available. Those of us who perform precision calculations will continue to require time transformations, even if the leap seconds are eliminated going forward. If you want to hide leap seconds from public view, simply coordinate public clocks to TAI or GPS time!
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Date=12_July_2011 , 17h28
Family Name = Johnson
First Name = Thomas
Institute = National Geospatial-Intelligence Agency
Country = USA
Field of activity = Astronomy-Astrophysics Geodesy Geophysics
Response = response_1
While one may think that knowledge and understanding of our universe is a true goal of science, in reality, it is not. The ultimate goal of science and its pursuit of greater knowledge is for the improvement of society. While predicting and keeping UTC aligned with the earth's rotation is not an easy task, it has benefits to society and therefore, should be maintained. For example, there are many users of UTC from around the world that have built their systems on the assumption of UTC being coordinated with the earth rotation. The decoupling of these systems would result in a great deal of work and financial expense to correct, all of which is unnecessary.
Furthermore, this is one indirect benefit to having leap seconds. Every time a leap second is inserted, the public media has to reach out to the scientific community to educate its consumer on the physics behind the need for this adjustment. Therefore, the general population gets a science lesson reminding them of the importance of astronomy and geophysics in their daily lives.
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Date=12_July_2011 , 17h42
Family Name = Stefan
First Name = Krista
Institute = Royal Astronomical Society of Canada
Country = Canada
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=12_July_2011 , 17h42
Family Name = Capitaine
First Name = Nicole
Institute = Bureau des longitudes& Paris Observatory
Country = France
Field of activity = Astronomy-Astrophysics Celestial-mechanics Geodesy
Response = response_2
- Separating the two concepts (angle for UT1,time for UTC) would be an improvement for high-accuracy applications.
- UT1 is defined by a conventional linear relation to ERA and benefits from the accuracy of that angle; for its best scientific use, that angle varying with time must be referred to an uniform time scale.
- The definition of UT1 is such that it is kept approximately (but not strictly) in phase with the mean solar time; so it in fact differs from the mean solar time +12 h and the difference is increasing with time.
- The definition of UTC based on leap seconds was designed to provide sufficient approximation to UT1 to celestial navigation; this is obsolete. For scientific applications, the use of the best uniform time scale is required (without leap seconds).
- If leap seconds are removed, the gap between UTC and UT1 will reach 3 min in 2100, 30 min in 2700, differences that are below those between legal time and solar time (+12h) that we tolerate.
- Scientific applications requiring prediction of UT1-UTC, such as precise astronomical ephemerides, can be established based on an IERS UT1-UTC prediction, leading to an accuracy at least as good as access to the UT1 derived from UTC with leap seconds.
- The responsibility of the IERS will be increased with the new interesting charge of providing predictions of the difference between UT1 and UTC, or UT1(UTC), in order to provide access to UT1 in real time. These values can easily be disseminated by positioning systems, such as GPS, which would give access to UT1 in real time to a wide categories of users.
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Date=12_July_2011 , 17h48
Family Name = Mabie
First Name = Justin
Institute = NOAA
Country = USA
Field of activity = Space-sciences
Response = response_1
No such change in the defintion of UTC should be considered. Instead, the community should propose a new timescale that is referenced off of UTC. There are several reasons for this.
1) It seems there is no proposed mechanism for the transition, between conversion of data to the new timescale or to update algorithms, instruments, and models that depend on the current definitoin of UTC.
2) Any change in the defintion of UTC would require a secondary timescale so that conversions can be made from the old defintion to the new definition. Any such timescale would in of itself serve the same purpose as the proposed change and is therefore unnecesarry.
3) This propposal would create unnecesarry confusion that could be avoided with an alternate such as the option of creating a new timescale.
4) Any errors or failure to adequately track conversions from the old to the new defintions could seriously effect research, particularly with regard to dynamics on timescales of one second or less. It should be noted that international metadata standards, although robust, do not even adequately address the needs of modern datasets, and are not used sufficiently to provide the capabilities for which they are intended. Certainly, application of a redefined timescale would add serious problems to meatadata tracking. In addition to this, historical datasets that have not yet been fully modernized, do not abide by any metadata standard and risk having their proper time stamps corrupted during the modernization process.
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Date=12_July_2011 , 18h09
Family Name = wilson
First Name = keith
Institute = Jet Propulsion Laboratory
Country = USA
Field of activity = Geodesy
Response = response_1
I am also concerned about the change in delivery of the dEps, dPsi,EOP parameters. These seem to lag their dX and dY counterparts by 1 month. Is there a way to convert these dX and dY parameters to dEps and dPsi?
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Date=12_July_2011 , 18h14
Family Name = Byun
First Name = Sung
Institute = Jet Propulsion Laboratory
Country = US
Field of activity = Celestial-mechanics Geodesy Geophysics
Response = response_3
If there is no leap second (keeping up with Earth rotation) what is the point of having UTC time scale? It doesn't have much meaning other than some offset from TAI. But I do understand that inserting UTC will become more frequent in the future and will become quite a nuisance. I am wondering there has been enough discussion regarding introducing 'leap minute' instead of leap second.
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Date=12_July_2011 , 19h12
Family Name = Horan
First Name = Karen
Institute = NOAA
Country = USA
Field of activity = Space-sciences
Response = response_4
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Date=12_July_2011 , 19h24
Family Name = Haywood
First Name = Gerald
Institute = Jubilee Office Supplies
Country = England
Field of activity = Business.
Response = response_1
It isn't broken.
Please don't fix it.
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Date=12_July_2011 , 19h31
Family Name = Melnick
First Name = Jorge
Institute = ESO
Country = Chile
Field of activity = Astronomy-Astrophysics
Response = response_1
Human time is a measure of the position of the Sun on the sky, which is determined by the rotation of the Earth and the potion of the Earth on its orbit around the Sun. Decoupling human time from the rotation of the Earth would take humanity one step further on the path to virtual existence. This is probably inevitable, but should be delayed as much as possible. Our organisms are still ruled by night/day cycles.
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Date=12_July_2011 , 20h22
Family Name = FRANCOU
First Name = GERARD
Institute = OBSERVATOIRE DE PARIS - SYRTE
Country = FRANCE
Field of activity = Astronomy-Astrophysics Celestial-mechanics Geodesy
Response = response_1
No comment
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Date=12_July_2011 , 20h23
Family Name = Bolotin
First Name = Sergei
Institute = NVI, Inc./NASA GSFC
Country = USA
Field of activity = Astronomy-Astrophysics Geodesy
Response = response_1
I believe that redefining of UTC time scale is unwise move. If one-second leap time adjustment is too complicated for civilian time keeping they can invent an appropriate time scale or use one of already existing continuous time scales, e.g. TAI.
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Date=12_July_2011 , 20h36
Family Name = Podesta
First Name = Ricardo
Institute = Observatorio Felix Aguilar (OAFA)
Country = San Juan, Argentina
Field of activity = Astronomy-Astrophysics Geodesy
Response = response_1
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Date=12_July_2011 , 21h05
Family Name = Boyson
First Name = Andrew
Institute = Home
Country = UK
Field of activity = Time enthusiast
Response = response_1
Would like to see NTP provide TAI. Internal PC clocks and file timestamps in TAI.
PCs could easily adjust the displayed time from infrequently downloaded leapseconds and daylight savings information.
Telescopes could map TAI against predicted earth rotation to provide an accurate position.
in a few thousand years we would need to redefine the earths angular second as some fraction of the TAI second in order to not exceed more than about 10 leap seconds per year.
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Date=12_July_2011 , 21h16
Family Name = Abarca del Rio
First Name = Rodrigo
Institute = DGEO
Country = Chile
Field of activity = Geodesy Geophysics Space-sciences
Response = response_2
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Date=13_July_2011 , 00h32
Family Name = young
First Name = larry
Institute = jet propulsion lab
Country = United States
Field of activity = Space-sciences
Response = response_2
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Date=13_July_2011 , 02h15
Family Name = Wildermann
First Name = Eugen
Institute = Universidad del Zulia
Country = Venezuela
Field of activity = Geodesy
Response = response_1
The current close connection with earth rotation seemed to me a great advantage of UTC, so eliminating this purpose UTC afterwards mainly will be a simple TAI offset. I don't see much sense of this at my current workspace (I'm interested at UTC TAI difference mainly for tide calculations for precise gravity observation would be influenced).
Sincerely, Yours
Eugen Wildermann
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Date=13_July_2011 , 02h45
Family Name = Carter
First Name = Bill
Institute = University of Houston
Country = USA
Field of activity = Geodesy
Response = response_1
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Date=13_July_2011 , 03h02
Family Name = HU
First Name = Songjie
Institute = Aerospace Flight Dynamics Lab
Country = China
Field of activity = Celestial-mechanics Space-sciences
Response = response_1
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Date=13_July_2011 , 03h09
Family Name = McGlaun
First Name = Daniel
Institute = none
Country = USA
Field of activity = Astronomy-Astrophysics
Response = response_1
I am an advanced amateur total eclipse chaser, involved also with calculating local circumstances. I see no tangible benefit to modifying the current definition of UTC; in fact, I see that for the purposes of maintaining the ability to perform historical calculations, the community would have to maintain two different sets of time measurement.
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Date=13_July_2011 , 04h43
Family Name = Senne
First Name = Joseph
Institute = Univ. of Missouri Science & Technology
Country = USA
Field of activity = Geodesy
Response = response_1
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Date=13_July_2011 , 07h55
Family Name = Roberto
First Name = Roldan
Institute = European Satellite Services Provider
Country = Spain
Field of activity = GNSS
Response = response_2
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Date=13_July_2011 , 09h59
Family Name = De Greef
First Name = Didier
Institute = ESSP
Country = Spain
Field of activity = Navigation
Response = response_1
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Date=13_July_2011 , 10h03
Family Name = Loyer
First Name = Sylvain
Institute = CLS
Country = FRANCE
Field of activity = Geodesy
Response = response_1
Unless with a large concensual opinion to change something,
it is better to keep the conventional usages as they are,
since "they are JUST conventions".
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Date=13_July_2011 , 11h24
Family Name = DENIS
First Name = Carlo
Institute = IAGO Liège
Country = Belgium
Field of activity = Geodesy Geophysics
Response = response_1
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Date=13_July_2011 , 11h30
Family Name = Piriz
First Name = Ricardo
Institute = GMV
Country = Spain
Field of activity = Celestial-mechanics Geodesy Geophysics
Response = response_1
Our department is involved in software development for GNSS orbit determination, timing, and positioning. In general we are quite satisfied with the current definition of UTC, leap seconds do not pose a problem for us. In any case, for detailed UT1 information we need to access specific IERS files, and this would not change if the UTC definition changes, so there is no impact. So the only benefit for us of a new UTC definition would be a constant offset between GPS Time and UTC, this means that we would have one interface less, we would not need to update GPSt-UTC when leap seconds happen (normally a text file in our system). On the other hand, having UTC tied to UT1 (current definition) is very nice for approximate calculations and simple software tools. For example, if you are using Two Line Elements (TLEs) to calculate approximate satellite orbits, it is quite useful to know that if you interpolate the model using UTC (current) instead of UT1 the resulting accuracy will be within the noise of the TLEs. There is also the issue of backward compatibility, if the UTC definition changes, there might be some side effects in our software that could make it fail, we would have to review the current code carefully. From a "philosophical" point of view, I feel more comfortable knowing that UTC, the time on my watch, is also linked to the Earth rotation and not only to atomic clocks, I believe the current definition is a good compromise between the "two worlds" and that is why it was invented.
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Date=13_July_2011 , 15h42
Family Name = Woodburn
First Name = James
Institute = AGI
Country = USA
Field of activity = Celestial-mechanics
Response = response_1
The proposed redefinition of UTC would cause a gradual degradation of many satellite systems which assume alignment between UT1 and civil time. While these systems could be updated, at considerable cost, I am concerned that many operators or users of these systems may not even be aware of the assumption and therefore would not recognize the need for change. As the degradation would be very gradual, system performance would slowly suffer but perhaps not come to a breaking point until the redefinition of civil time was a distant memory.
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Date=13_July_2011 , 16h18
Family Name = Dries
First Name = Jan
Institute = VITO
Country = Belgium
Field of activity = Earth Observation
Response = response_1
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Date=13_July_2011 , 16h35
Family Name = Chandler
First Name = John
Institute = Smithsonian Astrophysical Observatory
Country = USA
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=13_July_2011 , 17h10
Family Name = GUINOT
First Name = BERNARD
Institute = Obs. de Paris, Bureau des longitudes
Country = France
Field of activity = Astronomy-Astrophysics Geodesy Space-sciences Time-laboratory Former sailor (navigation officer)
Response = response_2
Present definition of UTC causes an ambiguity of date at the occurrence of a positive leap second which is potentially dangerous.
It favors the existence of several time scales differing by an integer number of seconds.
The present system was devised in 1972 in order to provide directly by radio time signals the needed accuracy of UT1 for celestial navigation (+/- 1 second).
This need (which may persist for safety reasons) can be fufilled by expressing hour angles in printed nautical ephemeredes as a function of a continuous UTC (based on a prediction which can be made at the second level over 3 years).
For a better precision, UT1 is easily available by internet in real time at the level of a few milliseconds.
I recall that a continuous UTC will diverge from UT1 by one or two minutes in 2100 and will reach half an hour toward 2500-2600. Presently the offset of legal time with respect to solar time may exceed two hours in some countries...
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Date=13_July_2011 , 17h59
Family Name = McCann
First Name = Stephen
Institute = Private
Country = United Kingdom
Field of activity = Telecommunication
Response = response_1
The rotation of the Earth is not constant. A system that allows dynamic updates must be maintained. Although a change to the definition of UTC will not be noticeable to the vast majority of people who use accurate time keeping, it is not irrelevant. Initially inconvenient 'leap seconds' will be no longer required, but after several decades errors will accrue and at some point in the future a correction will be required. Who will care, as by then we'll all have passed on anyway.
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Date=13_July_2011 , 19h06
Family Name = Levine
First Name = Judah
Institute = National Institute of Standards and Tech
Country = USA
Field of activity = Telecommunication Time-laboratory
Response = response_2
It would also be possible to change the leap second to a leap hour when the dut1 correction was greater than about 2000 s. This method would limit the divergence of UT1 from UTC while minimizing the disruptions that occur when a leap second is realized.
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Date=13_July_2011 , 19h18
Family Name = McCarthy
First Name = Dennis
Institute = U. S. Naval Observatory
Country = USA
Field of activity = Astronomy-Astrophysics
Response = response_2
This questionnaire is poorly written and appears to be one of a series of such questionnaires. It makes the IERS look bad when it keeps sending out such poorly written and repetitive questionnaires. The second reference listed above is not in a peer-reviewed journal and should not even be listed as a reference. This questionnaire serves no useful purpose for either side of this issue.
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Date=13_July_2011 , 19h35
Family Name = Oltrogge
First Name = Daniel
Institute = 1Earth Research, LLC
Country = USA
Field of activity = Celestial-mechanics Space-sciences
Response = response_1
I feel that the current system has worked sufficiently well and there is intrinsic value in having UTC tied closely with Earth rotation. I understand the desire to eliminate leap seconds and the discontinuities that they cause. But I feel that we'd have to do extensive surveys, research and careful evaluation before we could determine the extent (likely quite a large impact) of software modifications, financial impacts and programmer/developer time required to eliminate the leap second (thereby potentially causing existing applications to 'break').
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Date=13_July_2011 , 19h45
Family Name = ACTIS
First Name = Eloy
Institute = Observatorio mAstronómico Félix Aguilar
Country = ARGENTINA
Field of activity = Astronomy-Astrophysics Geodesy Satellite Laser Ranging
Response = response_1
Current definition of UTC works very good and I don't feel neccessity of changing it.
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Date=13_July_2011 , 19h58
Family Name = Kouprianov
First Name = Vladimir
Institute = Pulkovo Observatory
Country = Russia
Field of activity = Astronomy-Astrophysics Space-sciences
Response = response_1
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Date=13_July_2011 , 21h23
Family Name = Connors
First Name = John
Institute = Private Individual
Country = USA
Field of activity = Astronomy-Astrophysics GPS commercial user, Astro & Celest Nav
Response = response_1
After thoroughly reading the provided references, the cost of changing the UTC leap second system / time standard (ref #2, V The Debate, D Costs of Changing) is not justified or technically warranted. The assumptions favoring the change are weak and favor academia and the scientific community. The commercial realm and public “users” are not well represented in these papers and government (tax payers), including commercial end users, are expected or assumed to absorb the cost (of redesign). Removing the leap second or making UTC “more” dynamically linked to the earth’s rotation is an expensive step backwards. John Connors 1520EDT Wed 7-13-2011 lunarnightowls@juno.com
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Date=13_July_2011 , 23h36
Family Name = Simpson
First Name = David
Institute = NASA Goddard Space Flight Center
Country = United States of America
Field of activity = Astronomy-Astrophysics Celestial-mechanics Space-sciences
Response = response_1
Keep UTC defined as it currently is. The most compelling reason for eliminating leap seconds seems to be that they will have to be introduced with increasing frequency in the future; however, that should not become an important concern for several centuries. Meanwhile, eliminating leap seconds now would leave us with four time atomic scales that differ from TAI only by a fixed offset (TAI, TT, GPS, and UTC), while providing no atomic-based time scale that maintains synchronization with UT1 (an important consideration for civil timekeeping). Dropping leap seconds from the definition of UTC now would be, at best, premature.
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Date=14_July_2011 , 01h09
Family Name = Shawhan
First Name = Peter
Institute = University of Maryland
Country = USA
Field of activity = Astronomy-Astrophysics
Response = response_2
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Date=14_July_2011 , 04h25
Family Name = Bizouard
First Name = Marie-Anne
Institute = Laboratoire de l'Accelerateur Lineaire
Country = France
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=14_July_2011 , 07h54
Family Name = Cannon
First Name = Kipp
Institute = Canadian Institute for Theoretical Astr.
Country = Canada
Field of activity = Astronomy-Astrophysics
Response = response_1
The motivation for removing the leap seconds from UTC is a mystery.
If UTC is not the correct time scale for an application, then there are many more to choose from. UTC is just one of a dozen or more time scales that are in regular use: TAI, UT0, UT1, UT1R, UT2, UT2R, UTC, GMST, GPS time, Julian day number, Unix time, .... In particular, several of them are atomic time scales free of leap seconds. For example, TAI, the count of GPS seconds, Unix time, and so on. Anyone who wishes to use a leap-second-free atomic time scale for their application is already free to use one of these. The conversions between these time scales and UTC are simple and well-documented.
-Kipp
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Date=14_July_2011 , 10h08
Family Name = McIver
First Name = Jessica
Institute = University of Massachusetts Amherst
Country = United States
Field of activity = Gravitational wave physics
Response = response_1
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Date=14_July_2011 , 11h52
Family Name = Skinner
First Name = Laurence
Institute = -
Country = England
Field of activity = Host an NTP Pool time server
Response = response_2
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Date=14_July_2011 , 13h26
Family Name = Loh
First Name = Jürgen
Institute = Alpermann+Velte e.e. GmbH
Country = Germany
Field of activity = Telecommunication
Response = response_2
We're a manufacturer of Timecode systems for radio and television broadcasting stations. SMPTE/EBU Timecode is often used to synchronize the equipment to civil time.
Jürgen Loh
http://www.alpermann-velte.com
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Date=14_July_2011 , 20h28
Family Name = standish
First Name = e myles
Institute = caltech/jpl - retired
Country = usa
Field of activity = Astronomy-Astrophysics
Response = response_1
UTC now approximates the earth's rotation (within 0.9 seconds). There is a lot of software throughout astronomy and navigation which subtly makes use of this fact. To change it would cause many unforeseen problems.
e m standish
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Date=14_July_2011 , 20h40
Family Name = Scott
First Name = Stephen
Institute = Caltech/Owens Valley Radio Observatory
Country = USA
Field of activity = Astronomy-Astrophysics
Response = response_2
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Date=14_July_2011 , 22h18
Family Name = Poutanen
First Name = Markku
Institute = Finnish Geodetic Institute
Country = Finland
Field of activity = Geodesy
Response = response_1
It is a much deeper principle than a technical or practical question about the leap second. Quitting the leap second we accept that UTC is no more fixed to the rotation of the Earth and our concept of time is not related to the variation of day and night. But we cannot quit the fact that half of the Earth is illuminated by the Sun, half is in darkness, and due to the rotation of the Earth we see the regular variation of day and night. If we accept the concept that this has no meaning in our life, we can quit the connection of the UTC to the rotation of the Earth. We can as well quit then the time zones, length of 24h day or incompatible length of the year with leap days every fourth year. All these are as well technically possible. But if we want follow day and night variation, then within decades we'll need a leap minute or within millennia a leap hour... Are these any better than the leap seconds?
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Date=15_July_2011 , 01h15
Family Name = Boriani
First Name = Azelio
Institute = SSBT spa
Country = Italy
Field of activity = Digital TV broadcast equipment
Response = response_1
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Date=15_July_2011 , 07h41
Family Name = Spencer
First Name = Mark
Institute = Aligned Solutions
Country = Caada
Field of activity = Telecommunication Information technology
Response = response_1
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Date=15_July_2011 , 09h33
Family Name = Orlati
First Name = Andrea
Institute = INAF-IRA
Country = Italy
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=15_July_2011 , 09h51
Family Name = Young
First Name = Iain
Institute = n/a
Country = United Kingdom
Field of activity = Telecommunication Time-laboratory
Response = response_1
TAI and GPS timescales are already avaliable should folks need or want a timescale without leap seconds. It seems to make little sense to me to add a third.
Maybe we should consider having a different name for a UTC based timescale w/o leap seconds =
But changing the current standard is most likely to just cause confusion, espesially amongst the general public
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Date=15_July_2011 , 09h58
Family Name = Fenn
First Name = David
Institute = Of Materials
Country = UK
Field of activity = Astronomy-Astrophysics Telecommunication Materials engineering
Response = response_1
If it ain't broke, don't fix it!
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Date=15_July_2011 , 10h15
Family Name = Plant
First Name = Hannah
Institute = Physics
Country = England
Field of activity = Physics
Response = response_1
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Date=15_July_2011 , 11h10
Family Name = Maccaferri
First Name = Giuseppe
Institute = Institute of Radioastronomy
Country = Italy
Field of activity = Astronomy-Astrophysics Geodesy Space-sciences Time-laboratory
Response = response_1
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Date=15_July_2011 , 11h12
Family Name = Verkindt
First Name = Didier
Institute = LAPP, CNRS
Country = France
Field of activity = Astronomy-Astrophysics gravitational waves detection
Response = response_2
I prefer to put the operation of leap seconds addition when
getting the UT1 (or local time) and to have a universal UTC date which is earth independent.
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Date=15_July_2011 , 14h47
Family Name = Combrinck
First Name = Ludwig
Institute = HartRAO
Country = South Africa
Field of activity = Geodesy
Response = response_1
Changes required to existing software, precompiled library binaries etc. (some of which may not have original source code, so that they cannot be modified) will create chaos. The result will be unworkable and un-fixable software. Who will foot the bill for this? Who will do this work? It is easy enough to maintain UTC., so I say do not fix that which is not broken.
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Date=15_July_2011 , 15h15
Family Name = Hildebrand
First Name = Andreas
Institute = ALC NetworX GmbH
Country = Germany
Field of activity = Professional Broadcast
Response = response_3
Speed up Earth rotation accordingly...
If this does not work out, leave UTC as it is - there are many reasons why it has been defined the way it is. If it would be changed to TAI + offset, you could use TAI at first instance.
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Date=15_July_2011 , 17h04
Family Name = Hohenkerk
First Name = Catherine
Institute = HM Nautical Almanac Office (UKHO)
Country = UK
Field of activity = Astronomy-Astrophysics
Response = response_1
It is useful to have |UTC-UT1|<0.9s. Navigation almancs, produced in advance, may be inaccurate as the prediction of UT1-UTC at the time of production that is needed to determine GHA may not be good enough. Textbooks etc will become invalid. The fact that sunrise/sunset times repeat over a 4-year cycle will no longer be necessarily true. Science & Technology aught to be able produce a solution without haveing to drop leap seconds.
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Date=16_July_2011 , 03h06
Family Name = Pogorelc
First Name = Scott
Institute = USG contractor
Country = USA
Field of activity = Satellite Navigation / OD
Response = response_2
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Date=16_July_2011 , 17h12
Family Name = Fesler
First Name = Jason
Institute = Yahoo, Inc
Country = USA
Field of activity = Internet related industry
Response = response_2
UTC affects *every computer* on this planet. And every OS implements coping with it differently. The last leap second event caused a global outage for me - across 50,000+ machines, and affecting 100M+ customers - due to a bug in the way leap second was handled. We now have to test every kernel version we operate (300+ kernels across 300,000+ machines) to simulate leap second.
Even without a hard lock up, leap seconds across devices that don't handle leap second correctly (not in the kernel, or ntpd not receiving the notice 24 hours in advance) cause the machines to have to skew to make up for it. This means that around the event, I can't correlate events between machines. Not until everything is back within tolerance.
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Date=17_July_2011 , 17h22
Family Name = Schoedel
First Name = John
Institute = Myself
Country = USA
Field of activity = Telecommunication
Response = response_1
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Date=17_July_2011 , 20h25
Family Name = Noel
First Name = Jean-Louis
Institute = Education
Country = Belgium
Field of activity = Telecommunication
Response = response_1
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Date=18_July_2011 , 05h39
Family Name = GULYAEV
First Name = SERGEI
Institute = Auckland University of Technology
Country = New Zealand
Field of activity = Astronomy-Astrophysics Geodesy
Response = response_1
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Date=18_July_2011 , 10h28
Family Name = kutoðlu
First Name = þenol hakan
Institute = zonguldak karaelmas university
Country = turkey
Field of activity = Geodesy
Response = response_2
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Date=18_July_2011 , 10h50
Family Name = Yule
First Name = Andy
Institute = u-blox
Country = UK
Field of activity = Telecommunication
Response = response_1
If it ain't broke, don't try to fix it!
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Date=18_July_2011 , 11h17
Family Name = Planesas
First Name = Pere
Institute = Observatorio Astronomico Nacional
Country = Spain
Field of activity = Astronomy-Astrophysics
Response = response_3
Leap minute
A leap minute could be introduced preferably at the end of June 30th
whenever the UT1-UTC difference is predicted to reach 60 s. The
announcement would have to be made several years ahead so by the time
it is applied the difference would be strictly larger than 55.0 seconds
(goal > 60 s) and smaller than 65.5 s. A new DUT1 would need to be
defined, and its resolution likely increased down to 1 ms to fulfill
high precision applications,
Main advantages:
- Keep UTC close to the mean solar time.
- Keep UTC's name and legal status.
- Fewer changes per century (TAI-UTC difference constant for decades),
- Able to cope with the UT1-TAI quadratic growth.
- DUT1 would become more widely used for those who really need it
(astronomers, navigators) resulting in higher precision calculations,
being a better representation of the astronomical time UT1.
Moreover:
- No need to allow for negative corrections.
- The first leap minute would take place in several decades, allowing
for all clocks, time-aware devices, software and time dissemination
standards to be able to cope with the extra ("60") minute.
- Might lead to the unification of the time systems by forcing them
to follow a unique (new) standard.
- A change in June 30th is less disruptive than on New Year's eve.
- The new DUT1 will give more visibility to those who determine it.
The new DUT1 could be disseminated in a 20-bit word:
- 1 sign bit
- 16 bits to cover time from 0 to 65535 ms.
- 1 measured/predicted bit
- 1 checksum bit
- 1 spare bit
A second 20-bit word could contain the DJM (as an integer), up to
the year 4595.
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Date=18_July_2011 , 13h43
Family Name = Possenti
First Name = Andrea
Institute = INAF-Osservatorio Astronomico Cagliari
Country = Italy
Field of activity = Astronomy-Astrophysics
Response = response_2
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Date=18_July_2011 , 16h15
Family Name = Cooper
First Name = Stanley
Institute = Johns Hopkins Univ. Applied Physics Lab.
Country = U.S.A.
Field of activity = Space mission timekeeping systems
Response = response_2
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Date=18_July_2011 , 17h04
Family Name = Colomer
First Name = Francisco
Institute = National Astronomical Observatory
Country = Spain
Field of activity = Astronomy-Astrophysics Geodesy
Response = response_1
Alternatively, the concept would remain for DUT1 but change only when added up to a "leap minute".
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Date=18_July_2011 , 19h02
Family Name = Talty
First Name = Richard
Institute = Science Horizons, Inc.
Country = USA
Field of activity = Geophysics
Response = response_1
It seems to me that there are two classes of users of UTC, and neither should have problems with leap seconds:
1) Users who do not need 1-second accuracy. Typical human scheduling (stores, classes, trains, etc.) operates with more than 1 second of slop. A leap second can be considered another type of unexpected time error and absorbed into that budget.
2) Users who need synchronization to 1 second or better. Stock trading, electricity grid, possibly traffic lights, etc.
Type 2 applications are, in practice, automatically synchronized to some UTC source. From this source, they can both measure their own time error, and obtain warning of upcoming leap seconds.
While it is theoretically possible to track UTC to within 1 second on 1-year timescales using a rubidium oscillator, it is far cheaper and more common to use a GPS receiver. Which provides ample warning of leap seconds.
Some UTC broadcasts provide little (DCF77) or no (MSF) leap-second warning, but that seems like a simpler technical problem to solve. As internet connectivity is more and more widely used, it gets easier to disseminate leap second information.
The great benefit of leap seconds over less frequent larger corrections to maintain 12h00 at roughly mid-day is that they can be ignored by a large number of time users, and that they are (barely) frequent enough to allow software to be tested.
People arguing for fewer, larger time scale jumps are just throwing the problem over the wall to some future legislators who will have to redefine local time to UTC offsets. Which will invariably not be dome in a coordinated way, leading to a mess similar to the introduction of the Gregorian calendar. (If hopefully without the Protestant Reformation.)
Given free choice, I would suggest more frequent smaller time corrections, but 1-second leap seconds are deeply entrenched and not worth changing now.
If you want a time scale without leap seconds, use TAI. Or GPS time. UTC, like all historical universal times, should remain basically coupled to the position of the sun.
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Date=19_July_2011 , 03h05
Family Name = Seago
First Name = John
Institute = Analytical Graphics, Inc.
Country = USA
Field of activity = Celestial-mechanics Space-sciences
Response = response_1
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Date=19_July_2011 , 10h24
Family Name = Brumfitt
First Name = Jon
Institute = ESAC
Country = Spain
Field of activity = Astronomy-Astrophysics Space-sciences
Response = response_2
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Date=19_July_2011 , 13h15
Family Name = Miguel J.
First Name = Sevilla
Institute = Facultad de Matematicas. UCM
Country = Spain
Field of activity = Geodesy
Response = response_1
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Date=19_July_2011 , 17h01
Family Name = Thornton
First Name = Tim
Institute = Smartcom Software
Country = UK
Field of activity = Astronomy-Astrophysics Geodesy
Response = response_1
Although dropping leap seconds would no doubt be convenient for some members of the scientific community, for everyone else it is necessary for "official" time to be in synch with "natural" time.
Also, it appears that the implications and means of management of time without leap seconds has not yet been fully thought out.
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Date=19_July_2011 , 18h37
Family Name = Santos
First Name = Marcelo
Institute = University of New Brunswick
Country = Canada
Field of activity = Geodesy
Response = response_1
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Date=19_July_2011 , 19h02
Family Name = Hrudkova
First Name = Marie
Institute = Isaac Newton Group of Telescopes
Country = Spain
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=19_July_2011 , 19h07
Family Name = Ghigo
First Name = Frank
Institute = National Radio Astronomy Observatory
Country = USA
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=20_July_2011 , 02h28
Family Name = Robinson
First Name = Rob
Institute = International Occultation Timing Assn
Country = USA
Field of activity = Astronomy-Astrophysics Celestial-mechanics Space-sciences
Response = response_1
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Date=20_July_2011 , 02h47
Family Name = Breit
First Name = Derek
Institute = IOTA
Country = USA
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=20_July_2011 , 09h30
Family Name = Quiles
First Name = Alfredo
Institute = ESA
Country = Netherlands
Field of activity = .
Response = response_1
..
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Date=20_July_2011 , 12h11
Family Name = Woan
First Name = Graham
Institute = University of Glasgow
Country = UK
Field of activity = Astronomy-Astrophysics
Response = response_2
My personal experience is that leap seconds create more problems than they solve, especially when implemented by non-experts, and that time differences between events should be easily computable.
One of the technicians at the Lords Bridge Observatory in Cambridge had tape measure with 2 feet missing in the middle. *He* had no problem using it, but I don't think it was a popular tape measure.
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Date=20_July_2011 , 14h49
Family Name = Gonzalez
First Name = Francisco
Institute = ESA
Country = The Netherlands
Field of activity = Geodesy
Response = response_2
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Date=20_July_2011 , 15h04
Family Name = Zebhauser
First Name = Benedikt
Institute = Hexagon Technology Center
Country = Switzerland
Field of activity = Geodesy Surveying
Response = response_1
Why having another timescale without leapseconds parallel to TAI?
That makes no sense. TAI can already accessed precise enough for the most applications in real-time e.g. from GPS time with a constant offset of 19 sec.
The introduction of leapseconds into UTC in 1972 was made for practical reasons that are still valid today. Many applications would have to acquire current corrections from services. Why complicating?
In case of unnecessarily changing the definition of UTC one would have to re-introduce a further time-scale with the current UTC definition including leap-seconds.
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Date=20_July_2011 , 17h35
Family Name = Buie
First Name = Marc
Institute = Southwest Research Institute
Country = USA
Field of activity = Astronomy-Astrophysics Celestial-mechanics Space-sciences
Response = response_1
Decoupling UTC from the Earth's rotation is sheer madness. We already have a
dynamical time definition and that serves for the computational needs of a
uniformly increasing time scale. UTC and its coupling to local time needs to
stay as it is. From my point of view there is no advantage to changing the
present system. The disadvantages are many, including the modification of ALL
data acquisition and data reduction software for astronomical and spacecraft
observations. The fact that this rewrite leads to no benefit argues strongly
against the change.
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Date=20_July_2011 , 18h58
Family Name = Graham
First Name = Francis
Institute = Kent State University
Country = USA
Field of activity = Astronomy-Astrophysics Space-sciences
Response = response_1
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Date=21_July_2011 , 00h34
Family Name = Ray
First Name = Paul
Institute = Naval Research Laboratory
Country = USA
Field of activity = Astronomy-Astrophysics
Response = response_2
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Date=21_July_2011 , 13h08
Family Name = Wood
First Name = Derek
Institute = Open University
Country = Scotland
Field of activity = Marine
Response = response_1
None
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Date=22_July_2011 , 12h24
Family Name = Doom
First Name = Claude
Institute = Hogeschool-Universiteit Brussel
Country = Belgium
Field of activity = Astronomy-Astrophysics
Response = response_2
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Date=22_July_2011 , 19h31
Family Name = Karimbi
First Name = Mahesh
Institute = Faculdade Ciência e Tecnologia / UNL
Country = Portugal
Field of activity = physical sciences
Response = response_1
Everyone agrees that the occurrence of astronomical events are not exactly periodic, so also, the relative movement of the Earth, Sun, Moon and some considered Stars. Since the known history and in known civilisations, the measurement of time depended on the astronomical events. Further, it is still practised at almost all the fields ranging from the civil life, cultural observations, military practices, sea navigations, to judge the future astronomical events etc., except, in the laboratory scientific experiments. Therefore, practice of having the 'leap' time magnitudes, such as, year, month etc., and recently, seconds have been in course. Further, in the regions where, 'day light saving phenomenon' is observed, the adjustment of the time is again a mandatory. The only difference in the adjustment process of the time in the all the cases, except 'leap second', is that they are predefined and predetermined. As with the latest technology, the job of predicting and publishing the introduction of leap second is already done by IERS twice a year, it can be well implemented for majority of the purposes except the laboratory scientific experiments.
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Date=22_July_2011 , 23h42
Family Name = Wheatley
First Name = Peter
Institute = University of Warwick
Country = UK
Field of activity = Astronomy-Astrophysics
Response = response_2
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Date=23_July_2011 , 01h40
Family Name = Douglas
First Name = White
Institute = NA
Country = australia
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=24_July_2011 , 03h46
Family Name = Anonymous
First Name = Anonymous
Institute = None
Country = USA
Field of activity = none
Response = response_1
If you want a timescale with a constant offset from TAI, why not just use TAI?
UTC is still important for keeping track of Earth's actual rotation (corrected for accuracy). The purpose of timekeeping is to keep a stable relationship with the cycles of the day and year. This proposed redefinition would end this link and leave UTC completely arbitrary. This will have a disastrous impact on professions such as astronomy, which require a timescale that corresponds with planetary cycles. Why rob it from them? If you hate leap seconds, use TAI, while people who need UTC can use it for themselves. The system, as it currently is, works.
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Date=24_July_2011 , 07h05
Family Name = Banhatti
First Name = Dilip G.
Institute = Madurai Kamaraj University
Country = India
Field of activity = Astronomy-Astrophysics Physics, Science Numeracy / Outreach
Response = response_3
Comments meant to generate a middle path between the two alternatives.
# In early 1950s, Megh Nad Saha headed a team of scientists charged with developing a suitable calendar. The team came up with a solar calendar displaced from our usual Jauary-to-December one, but otherwise marking time at the same rate, along with leap years & so forth, so as to serve festive Indian culture better. This was adopted legally by Government of India, and is, in principle, legal from then on, even to date. However, in practice, everyone in India uses what the world does, perhaps mainly for commercial reasons. In fact, very few people are aware that another "Indian" calendar IS (also) legal!
# For pulsar timing (especially), and pretty much all other time variable / cyclic astro phenomena, Julian Day (JD) is used. Actual observations have time markers of the observatory making them. Any astro calculation then must convert to JD using standard conversion which includes any jumps (like leap seconds).
(# Paul A M Dirac used laser lunar ranging data in a most imaginative way. Was his use of these data in the way he did possible only due to some subtle issue of timekeeping?)
# My preference: Retain both the alternatives for the different purposes where they are needed, with the overheads for the needed change(s) minimized / optimized in each of the two domains.
# I guess astrodynamicists essentially use the same standard data on timekeeping that astronomers (at least currently) use to a lesser extent. Eventually, we may have timekeeping tied to solar system barycentre.
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Date=25_July_2011 , 00h12
Family Name = Manchester
First Name = Richard
Institute = CSIRO Astronomy and Space Science
Country = Australia
Field of activity = Astronomy-Astrophysics
Response = response_2
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Date=25_July_2011 , 07h05
Family Name = Powers
First Name = Patrick
Institute = Formerly Logica plc
Country = United Kingdom
Field of activity = Information Technology
Response = response_1
We are in tune with the sun. We have an important circadian rhythm tuned to the sun.
This is the essence of
time as we experience it. High noon when the sun is at its apex is midday,
halfway between sunrise and sunset, not 13:23:34 DST (Digital Daylight
Standard Mean Civil Clock Time). We cannot get past our innate sense of
solar time, the rhythm and duration of solar cycles. It is part of our
being. This is what sundials show, true solar time.
Granted the change to atomic time is a minor adjustment from solar
astronomical time, at this time. But the difference is cumulative. The
difference will accumulate through the centuries. In the future we would be
getting up in the morning at 12:00 or whatever abstract number is defined by
vibrating Cesium atoms. The odd leap second can adjust for the slower
rotation of the earth. Is this better than the riots when an abrupt shift
like the Gregorian correction is required. Computers are easier to
reprogram than people.
It will simply not be possible for all humanity to be aware of a time measure that is out of synchronism with the sun and this will generate years of requests for a return to the present status. Let us not even go there.
"Cogito ergo sum". Thinking people rule, technology
serves.
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Date=25_July_2011 , 09h42
Family Name = Foschini
First Name = Luigi
Institute = INAF Osservatorio Astronomico di Brera
Country = Italy
Field of activity = Astronomy-Astrophysics Space-sciences
Response = response_1
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Date=25_July_2011 , 13h23
Family Name = McEnery
First Name = Julie
Institute = NASA/GSFC
Country = United States
Field of activity = Astronomy-Astrophysics
Response = response_2
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Date=25_July_2011 , 15h16
Family Name = Roth
First Name = Martin
Institute = AIP
Country = Germany
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=25_July_2011 , 17h54
Family Name = Noël
First Name = Fernando
Institute = National Astronomical Observatory
Country = Chile
Field of activity = Astronomy-Astrophysics
Response = response_2
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Date=25_July_2011 , 19h50
Family Name = Grandi
First Name = Steven
Institute = National Optical Astronomy Observatory
Country = USA
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=26_July_2011 , 21h40
Family Name = Rundle
First Name = Nicholas
Institute = Rockwell Collins
Country = USA
Field of activity = Telecommunication
Response = response_2
In satellite communications, time needs to be very accurate between terrestrial terminals and the payload on the space vehicle. The time source is entered from UTC. Since most computer systems have no notion of a leap second, they must be added to the UTC time in order to create the actual time used by the communications network. This creates enormous complexity especially when leap seconds are added.
Since the communications systems are all computer controlled, the notion of time in relation to the Earth's rotation is not important as it is to the human population.
Please redefine UTC to be uniformly increasing without leap seconds.
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Date=27_July_2011 , 03h14
Family Name = Brown
First Name = Kyle
Institute = Unassigned
Country = United States of America
Field of activity = Web Applications Programmer
Response = response_4
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Date=27_July_2011 , 10h39
Family Name = Ron
First Name = Cyril
Institute = Astronomical Institute of Acad. Sciences
Country = Czech Republic
Field of activity = Astronomy-Astrophysics Celestial-mechanics Geodesy Geophysics
Response = response_1
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Date=27_July_2011 , 16h04
Family Name = Kaplan
First Name = George
Institute = (Contractor to U.S. Naval Observatory)
Country = USA
Field of activity = Astronomy-Astrophysics
Response = response_1
Applications that require a continuous time scale (without leap seconds) should use TAI.
In previous discussion of this issue, the necessity of the proposed change has not been clearly articulated, while the consequences of the proposed change, for large numbers of software systems, have been discounted. A full assessment of the number of software systems that assume that UT1=UTC has not been carried out. In fact, such an assessment would be difficult to carry out as a limited exercise because the UT1=UTC assumption is often implicit.
Leap seconds are a well-defined international standard that, although inconvenient, are within the capabilities of current technology, just as they were within the capabilities of the technology of 1972. "Inconvenience" is not a justification for so fundamental a change.
Furthermore, the ITU is not the correct international entity to change the definition of the worldwide system of civil time. This is more than just a change to a radio signal; it involves the very definition of what we mean by civil time and potentially affects every person within the developed or developing world.
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Date=27_July_2011 , 20h02
Family Name = Pinto
First Name = Heitor David
Institute = NASA
Country = United States
Field of activity = Global navigation satellite systems
Response = response_1
The problems created by leap seconds are rare and manageable, and therefore do not justify the adoption of a time scale no longer related to the rotation of the Earth.
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Date=28_July_2011 , 08h11
Family Name = Mohasseb
First Name = Mohamed
Institute = Arab Acdemy for Science and Technology
Country = Egypt
Field of activity = Geodesy
Response = response_1
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Date=28_July_2011 , 10h53
Family Name = Vondrak
First Name = Jan
Institute = Astron. Inst.., Acad. Sci. Czech Rep.
Country = Czech Republic
Field of activity = Astronomy-Astrophysics Celestial-mechanics Geodesy
Response = response_2
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Date=28_July_2011 , 22h29
Family Name = Himwich
First Name = William
Institute = NASA GSFC
Country = USA
Field of activity = Astronomy-Astrophysics Geodesy
Response = response_1
It is more than that we are satisfied with the current definition of UTC. We depend on it. It is built implicitly into many systems that we use and support world-wide for radio astronomy and geodesy. It will be a significant perturbation on these systems, many extremely difficult to modify, if the definition changes.
If there is no way to stop eliminating leap seconds, the proposal to have a "leap hour" is unrealistic and appears to just be an attempt to make time coordination some one (who hasn't been born yet) else's problem. This option also has serious undesirable effect. A more realistic option with less undesirable effects would be a "leap minute", but that would also defer difficult issues unresponsibly.
The fundamental problem is that most (if not all) computer operating systems as they exist now do not properly recognize leap seconds. This can be corrected now, in the present day, and would provide a long term solution.
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Date=29_July_2011 , 11h25
Family Name = Steeghs
First Name = Danny
Institute = University of Warwick
Country = United Kingdom
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=31_July_2011 , 20h15
Family Name = Ste. Marie
First Name = Paul
Institute = Amazon.com
Country = United States of America
Field of activity = software development
Response = response_1
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Date=01_August_2011 , 10h05
Family Name = Smith
First Name = Marlyn
Institute = British Astronomical Association
Country = GBR
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=01_August_2011 , 10h41
Family Name = Boomkamp
First Name = Henno
Institute = IAG WG 1.1.1 / ESOC
Country = Germany
Field of activity = Geodesy Space-sciences
Response = response_3
The essence of the current UTC definition is its sub-second offset from UT1. Take that property away, and UTC no longer exists: it becomes identical to TAI apart from the arbitrary constant offset. The discussion on stopping further leap seconds is therefore equivalent to a proposal for shifting the origin of the TAI time by the arbitrary amount of 34 seconds, and calling this shifted TAI scale "UTC", as if it is significantly different from TAI. It is not: it is exactly the same as TAI, apart from an arbitrarily different origin. The origin of TAI is already arbitrary, so what would be the point in having this UTC scale in parallel to it?
Arguments in favor of stopping further leap seconds are usually related to software issues, or to the political authority of announcing a formal leap second. We have always managed to live with these issues in the past. Furthermore, the increasingly important reprocessing activities of the scientific community imply that our software will forever have to be capable of dealing with past leap seconds (historic data often has UTC time stamps), even if no new leap seconds would occur in the future. The software argument is therefore rather weak.
Our "other preference" is therefore as follows. We introduce a new UTC definition without leap seconds, but call it "TAI2000" rather than UTC. Instead of the arbitrary shift of 34 seconds between the UTC and TAI origin, we use the offset at the J2000 epoch, which was 32 seconds. This (forever) constant offset between TAI and TAI2000 is just as arbitrary as when we would keep the current number of leap seconds frozen forever, but at least there would be some physical meaning to it. Also, it makes sense to call this new scale TAI2000 rather than UTC2000. The old UTC should then continue as it is - with leap seconds - because that is the only relevant way in which UTC is different from TAI.
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Date=01_August_2011 , 13h39
Family Name = Boot
First Name = Teco
Institute = Inifinity Networks
Country = Netherlands
Field of activity = Telecommunication
Response = response_2
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Date=01_August_2011 , 19h30
Family Name = Gordon
First Name = David
Institute = NASA/GSFC
Country = USA
Field of activity = Astronomy-Astrophysics Geodesy
Response = response_1
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Date=01_August_2011 , 21h33
Family Name = Ruppert
First Name = Lyle
Institute = Ball Aerospace & Technologies Corp
Country = US
Field of activity = Celestial-mechanics Geodesy Space-sciences
Response = response_1
UTC as presently defined is an optimal choice of timescales in many applications. Other options are already available for applications in which a leap second might be inconvenient.
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Date=02_August_2011 , 13h26
Family Name = Luzum
First Name = Brian
Institute = USNO
Country = USA
Field of activity = Geodesy
Response = response_2
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Date=02_August_2011 , 15h45
Family Name = cook
First Name = mike
Institute = n/a
Country = France
Field of activity = Time-laboratory
Response = response_3
The issue in hand is more than redefining UTC.
There are three requirements of time transmission that are met by the current recommendation of ITU-R TF.460-6.
a) Ticks of SI seconds, used by all.
b) Current value for DUT1.
c) A civil time scale, UTC, used world wide as a legal time scale, directly descending from and now synonymous with GMT which is still the legal definition in many countries laws.
The current proposition to change ITU-R TF.460 provides for ONLY the first of the above requirements. Although there has been no consensus on change in the last 10 years, I think the the whole issue should go back to ITU-R WPA7 with the remit to devise a recommendation that includes ALL of the above requirements and to postpone any change until that recommendation is finalised. The current system will be quite satisfactory out to about 2300. As there is no need for precipitation, WPA7 could start from scratch and ask what is and will be required in future for time transmission.
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Date=03_August_2011 , 13h11
Family Name = Visser
First Name = Hans
Institute = Fugro Satellite Positioning BV
Country = Netherlands
Field of activity = Geodesy
Response = response_2
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Date=04_August_2011 , 01h55
Family Name = Sutton
First Name = Jordan
Institute = Cascade Climatology Consulting Corp.
Country = United States
Field of activity = Meteorologist
Response = response_1
I feel that the leap second is necessary to keep time as accurate as possible. There can be no "perfect clock" or "perfect calendar", since the earth's rotation is not constant, and therefore, the earth is not a perfect timekeeper. Due to tidal drag, the earth's rotation rate is slowing down at a very slight rate; the slowing is measured by the quantity delta-t, which is usually expressed in seconds. So, when delta-t increases by a second, a leap second becomes necessary.
Over time, leap seconds will be needed more frequently due to the fact that delta-t is proportional to the square of elapsed time. Currently, a leap second is typically added every one to two years. As time progresses, leap seconds will be needed several times a year, then every month, then every week, then every day, ..., and so forth. At this point, millenia into the future, it might be more logical to insert a leap minute, or better yet, perhaps once a century make accurate clocks that run just a bit slower, thus redifining the length of the second.
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Date=04_August_2011 , 04h50
Family Name = Channon
First Name = Tim
Institute = private
Country = UK
Field of activity = various technical fields
Response = response_1
The arguments in favour of a change are weak whereas longer term trust in a system which is consistent is vital.
The risk of unintended consequences are considerable. (side effects)
We had a good example of bad argument acting as a justification for change here in England. This was about a move of currency system to decimal. The bad argument was about newly introduced digital computers. Some years later the stupidity of the argument is forgotten, is a trivial problem for computing. Whether losing a human sized unit of measuring was good or bad is not the point here.
The degree of reliance on GPS etc. is a grave concern. Any argument about the dire consequences of trouble with GPS ought to raise questions about existing safety and fixed independently. If GPS internally needs a fixed time that is a GPS problem, could for example be fixed elsewhere, time altered for display.
Awkward system updates? It is their job and the job of a competent design. Design out the problem.
From a design perspective, if you absolutely require local reliability you split the system, disconnect dependence. As an equipment designer I have had to do this on timing, whereas relying on an external clock as reference is cheap and asking for trouble. Plenty try to do this.
Live with it.
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Date=05_August_2011 , 23h15
Family Name = Levandowski
First Name = Robert
Institute = MacWhiz Technologies
Country = USA
Field of activity = Information technology; Finance
Response = response_1
UTC reflects the reality of the universe in which we live. The proposal to redefine UTC will cause UTC to drift away from reality, making it inaccurate. In the case of the systems I maintain, it will cause immense disruption due to the need to change code and procedures that currently understand UTC to include leap seconds. Accurate, synchronized time is vital for the operation of many computer protocols. It's also vital to tracking down issues that occur between systems used by different organizations, and a sub-second accuracy can be crucial in aligning events. The possibility that some organizations will use a redefined UTC while others use DUT1 would cause massive disruption. Please stop the insanity.
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Date=06_August_2011 , 23h14
Family Name = Little
First Name = Matthew
Institute = none
Country = USA
Field of activity = general public interested in metrology
Response = response_3
I would like the plan to be to correct UTC to UT1 when the divergence has reached an hour (3600 seconds) as that could be implemented as no net change as countries go to Daylight or Summer Time and such correction wouldn't have to be applied for much longer periods of time than the leap second. Everyone would still subtract an hour to go to the adjusted standard time at the end of that year's Daylight or Summer time. Yes, places that don't observe Daylight/Summer Time would have to change their clocks an hour at some point, I realize.
I believe it is appealing to keep the solar crossing of the zero meridian noon UTC *generally*, just that the correction can be allowed to accumulate to a quantity that can be planned for conveniently long in advance and then the next correction need not be worried about for another long period rather than worrying about "nudging" all the clocks so often.
However, looking at the situation from the point of view of correcting one's clocks, I note that when corrections are applied does not make much practical difference with my computer set via Internet time server and a separate clock set automatically via WWVB as these clocks would set themselves to the updated time and involve very little effort on my part whether the leap second policy is changed or not. Those relying on UT1 would likely need to track it just as much whether UTC is being corrected by leap seconds or not and we agree UT1 is the less predictable scale that needs to be tracked and analyzed regardless of agreement with UTC.
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Date=06_August_2011 , 23h26
Family Name = Skehan
First Name = Sean
Institute = City of Los Angeles - Government Agency
Country = USA
Field of activity = Transportation
Response = response_1
Significant amounts of transportation infrastructure in the USA are dependent on the accuracy of UTC for communications, coordination and operation. Leap seconds play an important part in keeping this equipment in sync. Allowing UTC to diverge from UT1 will in the long term be problematic. Also, the small and predictable leap second increments are much more tolerable than larger step adjustments proposed (leap minute or leap hour) and less troubling then letting UTC drift away from UT1. Please save the Leap Second!
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Date=07_August_2011 , 12h25
Family Name = King
First Name = Frank
Institute = British Sundial Society (Chairman)
Country = United Kingdom
Field of activity = Celestial-mechanics
Response = response_1
Leap seconds are as crucial for synchronising the daily rotation of the earth to
clock time as leap days are for synchronising the seasons to the calendar.
Please retain the current definition of UTC and the leap second.
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Date=07_August_2011 , 12h34
Family Name = mohamadi
First Name = jahanbakhsh
Institute = zanjan_university
Country = iran
Field of activity = Astronomy-Astrophysics Geodesy
Response = response_1
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Date=07_August_2011 , 21h58
Family Name = Kisselov
First Name = Ivo
Institute = n/a
Country = Bulgaria
Field of activity = Telecommunication
Response = response_1
As UTC is often reffered to and used in numerous calculations in all sectors and activites by a really very wide, diffuse and in fact hard to reach community at present, it would be better to leave it defined as it is today for official use.
After several decades when the new generation of satelite navigation and time keeping systems are fully developed and integrated, and our accuracy and modeling capabilities improve by a couple of orders, this probably would be reconsidered with a far longer perspective in mind, by a more understanding user community, and in a truly global manner.
Meanwhile - not to hamper the scietific work - probably a new "UTC0" (or so) can be defined that would drift away from solar time and progress uniformly (with the inevitable frequent improvements and changes to come with our development).
Competent researchers will no doubt be able to easyly handle such a change and make good use of it, without throwing hundreds of thousands of non-specialists into the next half-baked "measurement system bog" just because we have noticed an imperfection and want to try to impose a fix at once. Change is inevitable and needed, but should be done intelligently, not impatiently.
Ivo Kisselov
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Date=08_August_2011 , 14h36
Family Name = THEUILLON
First Name = Gwladys
Institute = SHOM
Country = France
Field of activity = Geodesy Geophysics Hydrography
Response = response_4
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Date=08_August_2011 , 15h32
Family Name = Hartmann
First Name = Wilfried
Institute = IGP, ETH Zürich
Country = Switzerland
Field of activity = Geodesy Geophysics
Response = response_2
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Date=09_August_2011 , 14h32
Family Name = Rodin
First Name = Alexander
Institute = Pushchino Radio Astronomy Observatory
Country = Russia
Field of activity = Astronomy-Astrophysics
Response = response_3
I prefer "leap minute" introduced every 50 or 100 years.
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Date=10_August_2011 , 12h31
Family Name = Sauve
First Name = Michael
Institute = Alien Technology, LLC
Country = USA
Field of activity = Astronomy-Astrophysics Telecommunication Time-laboratory
Response = response_1
All needs for a timescale which lacks discontinuities (leap seconds) can be fulfilled by using TAI. There is simply NO rational argument for redefining UTC, which is historically linked to earth rotation, and used for that reason, to be something it was never meant to be. There is no need for yet another time scale with a fixed offset from TAI such as GPS and SMPTE timescales.
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Date=12_August_2011 , 21h30
Family Name = Klepczynski
First Name = William
Institute = Global Timing Servcices, LLC
Country = USA
Field of activity = Astronomy-Astrophysics
Response = response_2
If UT1 is needed, it can easily be obtained from the IERS to even greater precision than that available through transmitted time signals.
In this day and age, it should be a relatively easy task to re-program computers to run at UT1 with known and predicted corrections to UTC. It is even possible to have a digital clock which keeps UT1 using the published offsets of UT1 from UTC if one is needed for guiding telescopes.
I see no technical reason for keeping the existing system other than TRADITION. Even for celestial navigation, the published corrections to UTC can easily be applied to sxetant observations.
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Date=13_August_2011 , 04h35
Family Name = Schuh
First Name = Harald
Institute = IGG, Vienna University of Technology
Country = Austria
Field of activity = Astronomy-Astrophysics Geodesy
Response = response_1
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Date=13_August_2011 , 04h43
Family Name = Ohnuki
First Name = Tohru
Institute = Northrop Grumman Aerospace Systems
Country = USA
Field of activity = Astronomy-Astrophysics Space-sciences
Response = response_1
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Date=16_August_2011 , 00h32
Family Name = Frankston
First Name = Bob
Institute = Frankston
Country = US
Field of activity = Information Systems
Response = response_2
We needn't fit all definitions of time into a single framework. Whether we call this UTC or not is secondary.
We do, however, need to recognize that times in databases since 1972 have been indeterminate since we can't be sure that leap seconds were honored and, in fact, most databases can't deal with leap seconds and interval calculations can't. For this reason we need to unwind leap seconds. This would be facilitated by adopting a designation that is explicit about being uniform since 1972.
We can then adopt measures appropriate to domains that need to take into account celestial objects and other considerations.
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Date=16_August_2011 , 09h39
Family Name = Davis
First Name = John
Institute = British Sundial Society
Country = UK
Field of activity = Celestial-mechanics Sundial design and consultancy
Response = response_1
Leap seconds are crucial to keeping timekeeping locked to the rotation of the earth. I (or my descendants) do not wish to have noon drift into the middle of the night.
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Date=16_August_2011 , 11h27
Family Name = Oja
First Name = Heikki
Institute = Helsinki University Almanac Office
Country = Finland
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=17_August_2011 , 09h25
Family Name = Gupta
First Name = Sanjeev
Institute = DCS1
Country = Singapore
Field of activity = Telecommunication Network Research
Response = response_1
Changing the definition of UTC will cause a discontinuity.
I have no objections to a non-leap-second scale, but there is no reason to use the same name. There is no shortage of new names that can be used for such a scale, or call it TAI-34.
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Date=17_August_2011 , 23h03
Family Name = Cabeen
First Name = Ted
Institute = UCSB
Country = USA
Field of activity = Telecommunication
Response = response_1
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Date=18_August_2011 , 04h52
Family Name = Altman
First Name = Jeffrey
Institute = OpenAFS
Country = United States
Field of activity = File system developer
Response = response_2
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Date=18_August_2011 , 05h32
Family Name = Buhrmaster
First Name = Gary
Institute = Gary Buhrmaster
Country = USA
Field of activity = Telecommunication
Response = response_1
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Date=18_August_2011 , 08h10
Family Name = Eggert
First Name = Paul
Institute = UCLA Computer Science Department
Country = USA
Field of activity = Software engineering
Response = response_1
My background is software engineering. I help maintain many widely
used computer programs that deal with leap seconds, including the GNU
C library
and the TZ (timezone) database
and code
. I see no real need
for this change, and some reasonable arguments against it, mostly in
terms of complexity of transitioning to software implementing the new
system.
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Date=18_August_2011 , 14h56
Family Name = Zijlstra
First Name = Mark
Institute = Royal Netherlands Navy / CAMS-ForceVisio
Country = the Netherlands
Field of activity = Astronomy-Astrophysics Celestial-mechanics Geodesy Defense
Response = response_2
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Date=18_August_2011 , 19h57
Family Name = Colebourne
First Name = Stephen
Institute = OpenGamma
Country = UK
Field of activity = Computing
Response = response_1
I believe it is fundamentally wrong for civil timekeeping to be altered in a way that separates us from the solar day and that this has moral and ethical issues beyond science or broadcasting. I also believe that is is wrong to continue to use UTC for something different to what the UT prefix implies. TAI already provides what this change seeks.
I believe that a large part of the problem has been computer systems that are not setup to deal with leap seconds, however Java via JSR-310 is bringing full leap second support and I expect others to follow. My experience as JSR-310 spec lead indicates that developers (and humans generally) realy like the concept of 24 hours of exactly 60 minutes of exactly 60 seconds, and they would prefer to see that maintained (such as via rubber seconds) rather than having to cope with an occasional 61 second minute. I believe that the best solution to the issues here are to publish leap seconds 5 years in advance, with the understanding that DUT may exceed 0.9 seconds by a small amount if the prediction is wrong. Leap seconds should be permitted at the end of any month.
I also believe that UTC-SLS (whether smoothed over 1000s, 600s or 1200s) should be more widely published as the standard mechanism for mapping TAI + leap seconds to civil time. Finally, I want to see the atomic duration of "SI seconds" renamed (to duronds?) allowing the "second" to be used for civil time. The duration of 1 second is 1 durond except near a leap, where it may be longer or shorter (see UTC-SLS).
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Date=19_August_2011 , 08h27
Family Name = Emanov
First Name = Alexey
Institute = Altay-Sayan branch of Geophysical Survey
Country = RUSSIA
Field of activity = Geophysics
Response = response_2
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Date=19_August_2011 , 17h50
Family Name = Vasconcelos
First Name = Manuela
Institute = Portuguese Geographic Institute
Country = Portugal
Field of activity = Geodesy
Response = response_1
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Date=19_August_2011 , 23h53
Family Name = Storz
First Name = Mark
Institute = Air Force Space Command
Country = USA
Field of activity = Astronomy-Astrophysics Celestial-mechanics Geodesy Geophysics Space-sciences Telecommunication
Response = response_1
The Office of the Secretary of Defense (through a letter from ASD/NII to the State Department - June 29,2009) has already agreed to support the elimination of leap seconds, but no earlier than January 1, 2019. Although no real cost estimate for upgrading Air Force Space Command software has been performed, many subject matter experts expect costs could be in the $100s of millions. A schedule risk could also be incurred if the complexity of the software upgrades is such that they cannot be tested and implemented by 1 Jan 2018 (date suggested by ITU-R).
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Date=20_August_2011 , 22h29
Family Name = Klein
First Name = Stanley
Institute = United States Power Squadrons
Country = USA
Field of activity = Celestial-mechanics
Response = response_1
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Date=22_August_2011 , 15h00
Family Name = Mäkinen
First Name = Jaakko
Institute = Finnish Geodetic Institute
Country = Finland
Field of activity = Geodesy Geophysics Metrology
Response = response_2
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Date=22_August_2011 , 18h35
Family Name = Fischer
First Name = Michael
Institute = Marin Amateur Radio Society
Country = USA
Field of activity = Telecommunication
Response = response_1
Thank you for maintaining the status quo!
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Date=22_August_2011 , 20h16
Family Name = Kerns
First Name = Carrol
Institute = Kerns Associates
Country = USA
Field of activity = Meteorology
Response = response_1
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Date=22_August_2011 , 21h13
Family Name = Deovlet
First Name = Benjamin
Institute = Stanford University
Country = United States of America
Field of activity = Telecommunication
Response = response_1
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Date=22_August_2011 , 21h23
Family Name = ABRAHAM
First Name = JAMES
Institute = RETIRED
Country = USA
Field of activity = Telecommunication
Response = response_1
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Date=22_August_2011 , 23h30
Family Name = Denny
First Name = Douglas
Institute = Ex-Institute of Measurement and Control
Country = England
Field of activity = Astronomy-Astrophysics Celestial-mechanics
Response = response_1
A common, globally used system, linked to the Earth's rotation/variation and adjusted to be within one second at all times, or better, adjusted to within 100milliseconds (or better) by more frequent and automatic adjustments, promulgated by the international time-standard radio systems, is the common-sense way forward for the future use by the maximum number of people with the least trouble to any of them.
Scientific use is more normally restricted to a relatively miniscule number of people and systems, and can be promulgated via GPS signal embedded data and is readily obtained for specialist use by specialist receivers. Let the few have the greater trouble obtaining a continuous dynamical time system.
Dynamical Time can be linked to pulsars or continue to be defined by the latest hydrogen maser, caesium fountain or other atomic systems technology.
Douglas Denny. BSc (Hons).
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Date=23_August_2011 , 00h26
Family Name = Posick
First Name = Steven
Institute = ESPN
Country = USA
Field of activity = Media and Broadcast
Response = response_1
The purpose of tracking time has historically been associated to the rotation of the earth and the suns position within the sky. What's to point of a time based system that does not reflect this? Who does it benefit and why? How will this help everyday software engineers/architects like myself in making software applications that function at a global scale (remember timezones)? Currently, UTC is used, if UTC is changed then the impact will be far reaching as most developers won't even understand the divergence. If someone needs a time standard like this for scientific applications, make a new standard. Leave the one everyone has become familiar with alone.
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Date=23_August_2011 , 05h09
Family Name = Bliss
First Name = Gerald
Institute = Retired
Country = USA
Field of activity = Telecommunication
Response = response_4
Just so we all are on the same tick !
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Date=23_August_2011 , 05h26
Family Name = Evans
First Name = Andrew
Institute = MSK
Country = USA
Field of activity = Telecommunication
Response = response_1
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Date=23_August_2011 , 07h25
Family Name = Ekne
First Name = IgnidzE
Institute = GS SB RAS
Country = Russia
Field of activity = Geophysics
Response = response_2
Remove leap seconds! Because it's very difficult to create programs with it support. As result today 99% of programs have no support of them. For example if we try to show graph of data in real time we should to do correction from system time (if system have support of it). And we should introduce correctly 60 second.
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Date=23_August_2011 , 09h19
Family Name = Stephansen
First Name = Helge
Institute = T-VIPS
Country = Norway
Field of activity = Broadcasting
Response = response_2
For synchronisation of Single Frequency Transmitters in DVB-T2 ETSI EN 302 755 v1.1.1 Number of UTC seceonds since 1.1 2000 is used as reference for time. The handling of leap seconds add a considerable complexity for equipment manufacturers and for operators in order to preper and pre-program for the insertion/removal of a leap second.
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Date=23_August_2011 , 11h06
Family Name = Cook
First Name = Bert
Institute = Member of American Radio Relay League
Country = United States of America
Field of activity = Telecommunication Amateur Radio
Response = response_1
Presently UTC is the world accepted time standard used in world wide radio communication. It is also the basis for the worlds established time zones. It would be very awkward to have to refer to another time standard and further a change wmight make it more difficult and more costly to maintain than the current method. I realize that while the atomic time standard may be necessary for some extremely delicate scientific needs in laboratories, etc; the present system is the easiest and less expensive system to maintain and use in my practice of Amateur Radio and Amateur Astronomy. Thank you. Bert H. Cook, K6CSL, Riverbank, CA, USA
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Date=23_August_2011 , 12h50
Family Name = Reis Paulino Cascalheira
First Name = Telmo José
Institute = Geographic of Portuguese Army
Country = Portugal
Field of activity = Geodesy GIS
Response = response_1
Avoiding the leap seconds, will bring with time some problems that we cannot figure out at the present time the consequences that will have. I strongly recommend that a deep study into this subject is done and assess all the consequences that might have. Only then the community is ready to discuss the subject.
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Date=23_August_2011 , 13h33
Family Name = Schaal
First Name = Ricardo
Institute = EESC- Universitu os São Paulo
Country = Brazil
Field of activity = GPS applications
Response = response_1
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Date=23_August_2011 , 13h43
Family Name = TRABANCO
First Name = JORGE
Institute = UNICAMP
Country = Brasil
Field of activity = Geodesy
Response = response_1
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Date=23_August_2011 , 15h17
Family Name = Martins
First Name = Paulo
Institute = Portuguese Army Geographic
Country = Portugal
Field of activity = Geodesy Geophysics
Response = response_1
It is very well described in the reference number two table 1 of the appendix the pros and the cons of the UTC redefinition. From the perspective of our institution this will bring additional and not quantified costs with no foreseen benefits.
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Date=23_August_2011 , 15h22
Family Name = Goncalves Ferreira
First Name = Vagner
Institute = Hohai University
Country = China
Field of activity = Geodesy
Response = response_2
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Date=23_August_2011 , 16h25
Family Name = Rui
First Name = Dias
Institute = Instituto Geográfico do Exército
Country = Portugal
Field of activity = Geodesy
Response = response_1
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Date=23_August_2011 , 18h14
Family Name = Aranha Ribeiro
First Name = Selma Regina
Institute = University State of Ponta Grossa - PR
Country = Brasil
Field of activity = Geodesy remote sensing data
Response = response_2
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Date=24_August_2011 , 05h08
Family Name = Calabretta
First Name = Mark
Institute = Australia Telescope National Facility
Country = Australia
Field of activity = Astronomy-Astrophysics
Response = response_1
I am a software engineer with over 25 years experience in astronomical software development and maintenance.
It is common for astronomical software to take advantage of the fact that UTC approximates UT1 sufficiently well to be used for purposes such as Doppler correction or low-precision calculation of apparent coordinates. If leap seconds are dropped, the approximation UTC ~= UT1 will degrade slowly over a period of years, only becoming obvious after decades.
Inevitably some, possibly much, software would not be adapted to the altered definition of UTC. The error may go unnoticed at first, leading progressively to ever more erroneous results over a timescale of years to decades. The famous mis-identification of the first "pulsar planet" in the early 1990s, due to an error in calculation of the Earth's ephemeris, illustrates the potential harm that might result.
It is difficult to say how much software may be affected without conducting an extensive y2k-type audit. Indeed, identifying potentially affected software, and remediating that found, would in itself would be an expensive undertaking for the astronomical community.
Dropping leap seconds would fundamentally alter the meaning of UTC, effectively turning it into yet another atomic timescale offset by an integral number of seconds from TAI. It would even devalue the meaning of "UTC" for the period before leap seconds were dropped. This would affect the timestamps recorded in a vast archive of astronomical data so that a distinction would have to be made between "UTC with leap seconds" before a particular date, and "UTC without leap seconds" after it.
Aside from astronomical considerations, there is an implicit assumption that UTC, as the basis for civil time, is tied to the motion of the Sun. The very existence of daylight savings time supports this observation. The proposal to drop leap seconds essentially ignores this. There are only vague notions of "leap hours", or resetting time zones in 600 years time when the error has accumulated to one hour. I feel that this aspect of the proposal has not been adequately addressed.
For these reasons I strongly oppose the proposal to drop leap seconds.
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Date=24_August_2011 , 07h58
Family Name = SUAGHER
First Name = Françoise
Institute = Association Astronomique de Franche-Comt
Country = France
Field of activity = Astronomy-Astrophysics Space-sciences
Response = response_1
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Date=24_August_2011 , 15h33
Family Name = ARANA
First Name = JOSÉ MILTON
Institute = FCT/UNESP
Country = BRAZIL
Field of activity = Astronomy-Astrophysics Geodesy
Response = response_1
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Date=24_August_2011 , 23h50
Family Name = Isaacs
First Name = Michael
Institute = BSS
Country = UK
Field of activity = Horology, gnomics
Response = response_1
Leap seconds are as crucial for synchronising clock time to the daily rotation of the earth asleap days are for synchronising the calendar to the seasons. Please retain the current definition of UTC and the leap second.
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Date=25_August_2011 , 08h20
Family Name = Mele
First Name = Francesco
Institute = INGV
Country = Italy
Field of activity = Geophysics
Response = response_1
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Date=25_August_2011 , 11h54
Family Name = Maria
First Name = Escuer
Institute = Instituto de Meteorologia
Country = PORTUGAL
Field of activity = Geophysics
Response = response_1
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Date=25_August_2011 , 14h26
Family Name = Earl
First Name = Zmijewski
Institute = Renesys
Country = USA
Field of activity = Telecommunication
Response = response_1
A change at this point would break A LOT.
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Date=25_August_2011 , 15h11
Family Name = Hansen
First Name = Tony
Institute = AT&T Laboratories
Country = USA
Field of activity = Telecommunication
Response = response_1
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Date=25_August_2011 , 15h22
Family Name = Adolf
First Name = Alexander
Institute = Condition-ALPHA Digital Broadcast Techno
Country = Germany
Field of activity = TV Broadcast
Response = response_1
We fully understand and support the need for a non-leaping and unconstrained time source. This will be very useful in many scientific and technical use-cases.
Due to the very widespread use of UTC in commercial applications, we would however be concerned over redefining UTC. It's major role in commercial applications is providing a time-zone neutral (and hence reliable) way of specifying points in time for applications which are linked to, or depend on human activities (e.g. radio/TV broadcast or air travel) and therefore need to be aligned with day/night cycles (i.e. Earth rotation). In this role, UTC has become a brand name, and has been referred to in literally hundreds of standards, and in countless computer software interfaces.
We would hence like to kindly suggest that - instead of redefining UTC - a new time source should be defined with the described properties. This would allow commercial implementations using UTC to realize a migration path towards the new time source. Whilst existing standards and implementations could remain unchanged, new standards and application designs could make use of the new time source. This would for sure be a commercially viable solution.
Redefing UTC with a 5-year deadline for updating all implementations would imply huge investments for the commercial sector, without any perceived or visible commercial advantage though. We are hence concerned that the de-definition approach could lead to the change being largely ignored outside the scientific community.
Hence our suggestion for defining a new time source.
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Date=25_August_2011 , 15h52
Family Name = Hanna
First Name = Stephen
Institute = Juniper Networks
Country = USA
Field of activity = Telecommunication
Response = response_1
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Date=25_August_2011 , 16h28
Family Name = Michael
First Name = Richardson
Institute = CREDIL
Country = Canada
Field of activity = Telecommunication
Response = response_1
Given that computers all over the world (except some of the toys made in Redmond), already have code to deal with leap seconds (and timezones), and we all use a standard set of TIC files maintained by NIST.gov, I see no advantage to
removing leap second calculations.
It isn't like we can remove that code, nor is that code particularly big.
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Date=25_August_2011 , 19h01
Family Name = Daniel
First Name = Christopher
Institute = British Sundial Society
Country = United Kingdom
Field of activity = Astronomy-Astrophysics sundial design & delineation
Response = response_1
Leap seconds are as important, indeed crucial for the synchronisation of clock time to the diurnal rotation of the Earth as leap days are for rectifying the calendar with the seasons. I see absolutely no point in abandoning the use of leap seconds, which have stood the test of time, and ask that the current definition of UTC be retained together with the leap second.
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Date=25_August_2011 , 20h06
Family Name = Ellermann
First Name = Frank
Institute = meta.wikimedia.org/wiki/Template:YMD2MJD
Country = Germany
Field of activity = Computer Science, Mathematics
Response = response_1
Whatever happens to UTC, I need POSIX timestamps based on 24*60*60 seconds per day, and Modified Julian Days counting "observed" days corresponding to various calendar dates.
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Date=25_August_2011 , 20h31
Family Name = McQuillan
First Name = Bill
Institute = Bill McQuillan
Country = USA
Field of activity = Telecommunication
Response = response_1
Making UTC exactly track TAI (with a constant offset?) is redundant. Why have two standards with the same characteristics?
If a user needs an atomic time without unpredictable "leaps" use TAI. Also, for consistency TAI should NOT be expressed in terms of terrestrial motions like days and years but rather in multiples of seconds (e.g., Kiloseconds, Megaseconds,...)
Computers that cannot handle leap seconds should be replaced by ones that were developed by competent engineers.
Leave UTC as-is for those of us that like our sun overhead at noon!
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Date=25_August_2011 , 22h17
Family Name = Carpenter
First Name = Brian
Institute = Individual expert
Country = New Zealand
Field of activity = Telecommunication Internet protocol design
Response = response_1
UTC diverging from UT1 would become a major headache for future generations. We should continue to support the mild inconvenience of leap seconds.
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Date=26_August_2011 , 04h21
Family Name = Chapin
First Name = Lyman
Institute = Interisle Consulting Group
Country = USA
Field of activity = Telecommunication
Response = response_1
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Date=26_August_2011 , 11h09
Family Name = Vesely
First Name = Alessandro
Institute = tana
Country = IT
Field of activity = Telecommunication
Response = response_1
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Date=26_August_2011 , 11h11
Family Name = Weilbier
First Name = Joerg
Institute = SIEMENS AG
Country = Germany
Field of activity = Telecommunication Energy distribution
Response = response_2
I think, the proposal will reduce unexpected malfunctions in computer networks, containing some components, can't handle current UTC definition of leap seconds right.
It's really difficult to detect errorneous (regarding leap seconds) components of a heterogene network and to predict behavior of functions, depending from exact time.
It seems to me, that almost all current implementations - errorneous _and_ well made - of UTC handling devices will work right with the new proposal.
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Date=26_August_2011 , 12h47
Family Name = Vicente
First Name = Raimundo
Institute = Faculty of Sciences,Lisbon
Country = Portugal
Field of activity = Astronomy-Astrophysics Celestial-mechanics Geodesy Geophysics
Response = response_1
In order to avoid the introduction of another discontinuity in the actual system of units,constants and parameters,employed in astronomy,geodesy and geophysics, which already presents lack of consistency.
I am,therefore, satisfied with the current definition of UTC which includes leap second.
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Date=26_August_2011 , 13h43
Family Name = Pereira
First Name = Jorge
Institute = Servicio Hidrografico y Oceanografico de
Country = Chile
Field of activity = Hydrography and Oceanography
Response = response_1
Many users of our products, as well as surveyors support point 1 and indicate they are satisfied with current definition of UTC
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Date=28_August_2011 , 16h20
Family Name = Heard
First Name = Charles
Institute = Private Consultant
Country = USA
Field of activity = Telecommunication
Response = response_1
For applications where leap seconds are significant nuisance, direct use of TAI would be appropriate. It is not necessary to redefine UTC for that purpose. On the other hand, if UTC were redefined to have a constant offset from TAI, the lack of a time scale tied to the Earth's rotation would necessitate inventing something very similar to the current UTC to replace it. So my strong preference is to leave it as is.
By way of background, I have in the past written software for test equipment to convert UTC (as reported from a commercial GPS receiver) to something with a constant offset from TAI for timestamping purposes, so I am aware of the issues involved.
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Date=28_August_2011 , 17h25
Family Name = Eichenstein
First Name = Yisruel
Institute = Jewish Calendar Institute - Scientist
Country = Israel
Field of activity = Astronomy-Astrophysics Celestial-mechanics Space-sciences Time-laboratory Jewish Time-Studies
Response = response_1
My opinion is that the proposed change in the concept of UTC in a way it will not keep pace with the diurnal rotation of Earth is a significant deviation from the way humanity is measuring time along the history and the way we always perceived the concept of Day and Second.
I think that just like there is an accepted consensus that the Calendar is synchronized with the annual revolution of the heavenly bodies, and there is no idea to change it, the same is with the UTC concept which is not different, and for sure it's not something which could be changed in a narrow assembly, but it needs a worldwide referendum which it's currently not possible, because of this my opinion is to strongly oppose such a redefinition in the UTC concept.
About the problem of the increasing amount of machines which depends on UTC, I think that's very easy to create a universal protocol which should be programmed in such a way it should easy accept the Leap Second, also regarding the Julian Day when measured according to UTC, it's possible to program that at the day a Leap Second will be added, already in the beginning of that day the Second of that day should be measured a 86,401 part of the Day and not a 1/86,400.
Regarding the problem that the number of Leap Seconds that's will be required to inset will increase during the next tens and hundreds of years, it's possible to introduce a system that every hundred years (or any other time span) should the length of the second be determined anew according the LOD at that time, so it will be avoided the need of frequent insertion of Leap Seconds.
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Date=28_August_2011 , 17h28
Family Name = Genut
First Name = Mordche
Institute = Jewish Calendar Institute - President
Country = Israel
Field of activity = Astronomy-Astrophysics Celestial-mechanics Space-sciences
Response = response_1
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Date=28_August_2011 , 20h51
Family Name = Vincent
First Name = Fiona
Institute = University of St.Andrews
Country = Scotland, UK
Field of activity = Astronomy-Astrophysics
Response = response_1
The abstract idea of "Time" is a concept which humans find difficult to deal with, but its embodiment in the cycle of day and night allows us to feel comfortable with it. I think it would be morally undesirable to divorce our time-keeping system from the basic rhythms of life.
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Date=28_August_2011 , 21h54
Family Name = Stapleton
First Name = Roger
Institute = University of St.Andrews
Country = UK
Field of activity = Astronomy-Astrophysics
Response = response_1
My work is on the control system for a 1m class telescope (built about 1960). Its pointing system is not super-accuate so I only need UT1+/-1sec to get the pointing accuaracy needed. This is at present supplied by UTC via the internet and the NTP service. If UTC is abandoned by the removal of leap seconds I require easy access to the error between UT1 of the new timescale. I have seen no suggestion that such a service will be part of the change. There will also be a cost in programming time to incorporate this service - assuming that it is created.
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Date=28_August_2011 , 22h21
Family Name = Bortzmeyer
First Name = Stéphane
Institute = AFNIC
Country = France
Field of activity = Telecommunication
Response = response_1
After reading the two excellent papers mentioned as reference, and after discussing the matter with several persons, I tend to think that the fundamental problem is the existence of several user communities, each with different (but perfectly legitimate) requirments. Because these requirments are different, there is zero chance to find a way to satisy them all with one time scale. The only solution is therefore to have several scales and to let each community choose the one which fits its requirments.
Of course, there are already several time scales. I feel that most of the needs of people who want the end of leap seconds would be satisfied by TAI (a very regular time scale, without "steps" and without link with the solar time). If, for one reason ot the other, TAI is not perfect for them, and there is no existing time scale suitable, it may be interesting to develop a new time scale (I'm not convinced it will be necessary: many proposals, such as the one for the "new UTC", are YATSCOT - "Yet Another Time Scale with a Constant Offset to Tai"). But using the term UTC for a new time scale seems confusing because people and software are now used to the existing definition of UTC.
The root cause of the dispute, I believe, is that too many people would like to have a "primary" time scale, one which is "more equal than others", hence the fight over UTC (actually, over the name "UTC"). The proper framework of thought would be, not only to have several time scales, but also to recognize them are "equal" and choosen at will by the different communities.
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Date=28_August_2011 , 23h05
Family Name = Arnold
First Name = Mathieu
Institute = Absolight
Country = France
Field of activity = Telecommunication
Response = response_1
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Date=28_August_2011 , 23h24
Family Name = Rascanu
First Name = Theodor
Institute = Institut für Kernphysik Frankfurt
Country = Germany
Field of activity = Astronomy-Astrophysics
Response = response_1
In my opinion there is no logic behind setting UTC constant to TAI, since in that case one could directly use TAI.
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Date=29_August_2011 , 11h05
Family Name = Ferreira
First Name = Rui
Institute = MOG Technologies
Country = Portugal
Field of activity = Broadcasting
Response = response_2
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Date=29_August_2011 , 12h15
Family Name = Da Silva Costa
First Name = Paulo
Institute = LNEG
Country = Portugal
Field of activity = Space-sciences
Response = response_1
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Date=29_August_2011 , 18h48
Family Name = OGDEN
First Name = Andrew
Institute = worshipful company of clockmakers
Country = republic of Ireland
Field of activity = Geophysics
Response = response_1
Leap seconds are crucial for synchronising clock time with the daily rotation of the earth. Please retain the current definition of UTC and the leap second.
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Date=29_August_2011 , 21h30
Family Name = Auerbach
First Name = David
Institute = Technical University Eindhoven
Country = Netherlands
Field of activity = Geophysics
Response = response_1
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Date=29_August_2011 , 22h45
Family Name = Mann
First Name = Christopher
Institute = Michael Fields
Country = USA
Field of activity = Agriculture
Response = response_1
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Date=29_August_2011 , 22h49
Family Name = Leneweit
First Name = Gero
Institute = Carl Gustav Carus-Institute
Country = Germany
Field of activity = Nanotechnology
Response = response_1
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Date=29_August_2011 , 22h52
Family Name = Winiwarter
First Name = Verena
Institute = IFF Social Ecology
Country = Austria
Field of activity = Environmental History
Response = response_1
The symbolic significance of giving up our attachment to natural rhythms should not be underestimated.
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Date=29_August_2011 , 22h58
Family Name = schaerer
First Name = alec
Institute = geography -- u of basel
Country = switzerland
Field of activity = integral methodology
Response = response_1
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Date=29_August_2011 , 23h19
Family Name = Weigl
First Name = Herwig
Institute = Dept of History, Univ. Vienna
Country = Austria
Field of activity = history
Response = response_1
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Date=30_August_2011 , 00h04
Family Name = Jacobi
First Name = Johanna
Institute = University of Berne
Country = Switzerland
Field of activity = Space-sciences
Response = response_1
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Date=30_August_2011 , 00h27
Family Name = Giorgini
First Name = Jon
Institute = NASA/Jet Propulsion Laboratory
Country = USA
Field of activity = Astronomy-Astrophysics Celestial-mechanics Space-sciences solar system ephemerides
Response = response_1
Redefining UTC and dropping leap-seconds must not be imposed on those already successfully using it for the mild or theoretical convenience of others. Perpetually troublesome communication problems with the ephemeris-using public would be introduced; it is not simply a numerical and software modification issue.
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Date=30_August_2011 , 04h06
Family Name = Woo
First Name = Wang Chun
Institute = The Hong Kong Observatory
Country = Hong Kong, China
Field of activity = Astronomy-Astrophysics Geophysics Time-laboratory
Response = response_2
1. Designing, operating and testing time service equipment for leap seconds require tremendous efforts, yet they are still error-prone as leap seconds are introduced only occasionally.
2. The possibility of leap seconds makes it impossible to compile calendar valid for decades/centuries.
3. It is difficult to explain to the public why leap seconds are necessary, given that the time shift of sunrise/transit/sunset occur over hundreds of years.
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Date=30_August_2011 , 04h39
Family Name = KOEHLER
First Name = Reinhard, Dr.rer.nat.
Institute = Carl Gustav Carus-Institut
Country = Germany
Field of activity = Geophysics Hydrodynamics in Pharmazeutics
Response = response_1
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Date=30_August_2011 , 07h32
Family Name = Heertsch
First Name = Andreas
Institute = Verein für Krebsforschung
Country = Switzerland
Field of activity = Medical devices
Response = response_1
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Date=30_August_2011 , 08h06
Family Name = FICHMEISTER
First Name = Hellmut
Institute = Graz University of Technology
Country = AT
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=30_August_2011 , 08h30
Family Name = Auerbach
First Name = Raymond
Institute = Nelson Mandela Metropolitan University
Country = South Africa
Field of activity = Agriculture
Response = response_1
It is important in my field to have the connection with the actual astronomical events to which time is related in terms of daylight, planetary cycles and seasons. Please keep it as it is!
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Date=30_August_2011 , 08h40
Family Name = RAMM
First Name = Hartmut
Institute = Hiscia
Country = Switzerland
Field of activity = Cancer research
Response = response_1
The Sun is the source of life - let's keep connected.
HR
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Date=30_August_2011 , 09h16
Family Name = SCHWARZ
First Name = Reinhard
Institute = Ordination
Country = Austria
Field of activity = Medicine
Response = response_1
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Date=30_August_2011 , 09h27
Family Name = Sutter
First Name = Christine
Institute = Institut für Stroemungswissenschaften
Country = France
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=30_August_2011 , 10h03
Family Name = Lukas
First Name = Dostal
Institute = none
Country = Czech Republic
Field of activity = Astronomy as hobby / medicin
Response = response_1
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Date=30_August_2011 , 10h07
Family Name = Baur
First Name = Felix
Institute = private
Country = CH
Field of activity = medicine
Response = response_1
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Date=30_August_2011 , 10h51
Family Name = Moser
First Name = Max
Institute = Institute for Physiology, Med Uni Graz
Country = Austria
Field of activity = Medicine, Physiology
Response = response_1
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Date=30_August_2011 , 11h08
Family Name = Schmitt
First Name = Tobias
Institute = Gabriel-Tech
Country = Germany
Field of activity = Telecommunication
Response = response_1
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Date=30_August_2011 , 11h10
Family Name = Seifert
First Name = Georg
Institute = Charité Universitätsmedizin Berlin
Country = Germany
Field of activity = Medicine
Response = response_1
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Date=30_August_2011 , 11h17
Family Name = Kranz, Christoph
First Name = Christoph
Institute = none
Country = Austria
Field of activity = pedagogic
Response = response_1
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Date=30_August_2011 , 11h21
Family Name = Landl
First Name = Richard
Institute = Bund der Freien Waldorfschulen
Country = Germany
Field of activity = pädagogical science
Response = response_1
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Date=30_August_2011 , 12h23
Family Name = Haberl
First Name = Helmut
Institute = Institute of Social Ecology, AAU
Country = Austria
Field of activity = Social Ecology
Response = response_1
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Date=30_August_2011 , 12h49
Family Name = Van der Wal
First Name = Jacob
Institute = Dynamension
Country = Netherlands
Field of activity = Medicine
Response = response_1
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Date=30_August_2011 , 12h50
Family Name = McKeeen
First Name = Claudia
Institute = Fachschule/Kindergartenseminar
Country = Germany
Field of activity = Medizin und Pädagogik
Response = response_1
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Date=30_August_2011 , 12h50
Family Name = Els
First Name = Ruitenberg
Institute = Dynamension
Country = Netherlands
Field of activity = none
Response = response_1
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Date=30_August_2011 , 13h18
Family Name = Crawford
First Name = Athalie
Institute = Quaker Peace Centre
Country = South Africa
Field of activity = Diversity
Response = response_1
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Date=30_August_2011 , 13h36
Family Name = Gelinek
First Name = Oskar
Institute = STENUM
Country = Austria
Field of activity = Environmental Consulting
Response = response_1
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Date=30_August_2011 , 13h45
Family Name = Barrett
First Name = Paul
Institute = US Naval Observatory
Country = United States
Field of activity = Astronomy-Astrophysics
Response = response_2
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Date=30_August_2011 , 14h03
Family Name = Kiene
First Name = Helmut
Institute = IFAEMM
Country = Germany
Field of activity = medicine
Response = response_1
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Date=30_August_2011 , 14h08
Family Name = Raderschatt
First Name = Bert
Institute = Praxis
Country = Germany
Field of activity = General practioner
Response = response_1
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Date=30_August_2011 , 14h24
Family Name = Merimaa
First Name = Mikko
Institute = Centre for Metrology and Accreditation
Country = Finland
Field of activity = Time-laboratory National Metrology Institute
Response = response_2
Considering seasonal deviations of the apparent solar time and quantization caused by time zones, leap seconds introduced to UTC are of minor importance to the general public. In a modern society, there are relatively few applications that require time synchronized to UT1, while leap seconds create problems in data logging, time stamping, telecommunication systems and time distribution services. Thus, a serious consideration should be given to stop corrections to UTC while the published difference between UTC and UT1 could be used in applications where UT1 is needed.
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Date=30_August_2011 , 14h57
Family Name = mayer
First Name = helmut
Institute = IPMR
Country = Austria Vienna
Field of activity = Rehabilitation Medizin
Response = response_1
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Date=30_August_2011 , 14h57
Family Name = Dr. Moravansky
First Name = Johann
Institute = priv pract
Country = Austria
Field of activity = Dr.med.
Response = response_1
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Date=30_August_2011 , 15h05
Family Name = Liess
First Name = Christian
Institute = HTWG Konstanz
Country = Germany
Field of activity = Fluid dynamics engineer
Response = response_1
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Date=30_August_2011 , 15h21
Family Name = Seelbach
First Name = Dr. Volker
Institute = Waldorfschool at Wangen / Allgäu
Country = Germany
Field of activity = Biology- and Chemistry-Teacher
Response = response_1
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Date=30_August_2011 , 15h44
Family Name = Volkmann
First Name = Juern-Hinrich
Institute = DGI
Country = Germany
Field of activity = Literature
Response = response_1
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Date=30_August_2011 , 16h33
Family Name = Rabethge
First Name = Helga
Institute = Naturheilmedizin
Country = Germany
Field of activity = Astronomy-Astrophysics Geisteswissenschaft
Response = response_1
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Date=30_August_2011 , 17h01
Family Name = Albonico
First Name = Hans-Ulrich
Institute = Cosmic Intuitive System Promotion CISP
Country = Switzerland
Field of activity = Biochronology
Response = response_1
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Date=30_August_2011 , 17h24
Family Name = Bauer
First Name = Hermann
Institute = school
Country = Germany
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=30_August_2011 , 17h27
Family Name = cimino
First Name = giancarlo
Institute = asl8 cagliari
Country = italy
Field of activity = Physician
Response = response_1
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Date=30_August_2011 , 17h32
Family Name = Malicky
First Name = Michael
Institute = Oberösterreichische Landesmuseen
Country = Austria
Field of activity = Informatics
Response = response_1
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Date=30_August_2011 , 17h35
Family Name = Allen
First Name = John
Institute = Edinburgh Univeristy
Country = Scotland
Field of activity = Astronomy-Astrophysics
Response = response_1
I acknowledge that UTC needs to follow the atomic time for astronomical and computing needs but it means changes to the way we read time from the sun (sundials being one example). Also it means that the meridan, now at Greenwich will effectively move slowly eastwards - which is confusing.
Can astronomers and computing people (the minority of the population) use another system that keeps in step with atomic time(I believe there are some already available)
Let us not confuse the oridinary folk with this change and keep the status quo!
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Date=30_August_2011 , 18h24
Family Name = Weaver
First Name = Nicholas
Institute = ICSI
Country = USA
Field of activity = Telecommunication
Response = response_1
The leap-second addition, when it occurs, is transparent to most computer users, programmers, etc, as systems are synced using NTP (Network Time Protocol) to UTC.
But if UTC, by removing leap-second addition, is allowed to diverge from Earth rotational time, when the accumulated divergence is over >1 minute, there will be pressure to redefine local times in terms of UTC - 60s, which will significantly disrupt a large number of computers, programs, etc, which rely on twin assumptions:
a) That UTC represents human-scale time
b) That the offset between UTC and local time doesn't suffer discontinuities.
The proposed change in definition of UTC will cause significant disruptions in the future on effectively every computer on the planet, as these assumptions about UTC ~= UT1 is baked into all these devices we use today.
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Date=30_August_2011 , 19h02
Family Name = Schwarz
First Name = Anneliese
Institute = Physik
Country = Austria
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=30_August_2011 , 19h11
Family Name = Schröter
First Name = Astrid
Institute = GCC
Country = China
Field of activity = Industry and Trade
Response = response_1
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Date=30_August_2011 , 20h16
Family Name = Schmidt
First Name = Martina
Institute = IPSUM
Country = Germany
Field of activity = physician
Response = response_1
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Date=30_August_2011 , 20h36
Family Name = Noest
First Name = Ingrid
Institute = privat
Country = Austria
Field of activity = Floristic
Response = response_1
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Date=30_August_2011 , 20h51
Family Name = Dickson
First Name = Brian
Institute = VeriSign
Country = USA
Field of activity = Telecommunication Networking protocols, equipment, service
Response = response_1
Since TAI exists, any need for a fixed offset from TAI can be achieve by... a fixed offset from TAI.
UTC is different from TAI because it is different than TAI.
Duh.
UTC exists for many reasons, and is an accepted standard, which is the basis for an entire category of time-related functions:
- astronomy (consistent and accurate measurements require consistent and accurate time)
- GPS
- GPS-derived super-accurate clocks for synchronized network transmission equipment
- GPS-derived super-accurate clocks for networking protocols
- GPS-derived super-accurate clocks for security logs
- GPS-derived super-accurate clocks for satellite communication buffering (Doppler effect cancellation)
- GPS-derived super-accurate clocks for keeping computers synchronized for inter-machine communication/coordination (filesystems, schedulers, etc.)
All of these require that UTC be consistent, and have not much to do with TAI-UTC drift.
All systems that derive nanosecond-level clocking from GPS, do so with knowledge of leap seconds, and do not experience frequency-shift off of TAI nanosecond-level clocking.
All systems that derive clock-face-time do so with knowledge of leap seconds, and maintain their synchronization across leap-second events.
Changing UTC to not implement leap-seconds can obviously be easily implemented, by not counting leap seconds. However, this achieves nothing of value, and does so at a significant detriment to every human activity that currently relies on UTC and GPS.
Please reject this, permanently.
Brian Dickosn
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Date=30_August_2011 , 20h58
Family Name = Jacobi
First Name = Michael
Institute = Institut für Strömungswissenschaften
Country = Germany
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=30_August_2011 , 21h23
Family Name = Kestel
First Name = Tobias
Institute = White Elephant DesignLab
Country = Austria
Field of activity = Industrial Design
Response = response_1
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Date=30_August_2011 , 21h26
Family Name = Dr. Kindt
First Name = Reinhard
Institute = Anthroposophical Society
Country = Germany
Field of activity = medical doctor
Response = response_1
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Date=30_August_2011 , 21h55
Family Name = Schwarz
First Name = Valentin
Institute = Weleda AG
Country = Germany
Field of activity = life science/microbiology
Response = response_1
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Date=30_August_2011 , 22h06
Family Name = Kröswagn
First Name = Armin Kröswagn
Institute = private
Country = Österreich
Field of activity = pediatrician
Response = response_1
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Date=30_August_2011 , 22h14
Family Name = Varga
First Name = Marta
Institute = TU Budapest
Country = Hungary
Field of activity = Celestial-mechanics Geodesy Space-sciences
Response = response_1
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Date=30_August_2011 , 22h17
Family Name = Jacobi
First Name = Martin
Institute = Sozialtherap. Gemeinschaften Ww e. V.
Country = Germany
Field of activity = musician (a=432 Hertz)
Response = response_1
No doubt to me - by shifting time one hour ahead what happens every year end of March time is spoiled enough. "Summer Time" to me means more worrying, more distress, less enthousiasm.
Redefining the second in the above way would mean wrong tone system; music would not have to do with human feelings any more. Never I can accept that.
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Date=30_August_2011 , 22h22
Family Name = Conradt
First Name = Oliver
Institute = Section for Mathematics and Astronomy, G
Country = Switzerland
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=30_August_2011 , 22h27
Family Name = Miller
First Name = Gary
Institute = Rellim
Country = USA
Field of activity = Time-laboratory
Response = response_1
Please do NOT do this! There are many GPS in the field that are over 20 years old and have no chance of a firmware update. Incompatible changes to a long established standard would lead to many problems.
Ain't broke, don't fix it.
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Date=30_August_2011 , 23h07
Family Name = jacobi
First Name = freimut
Institute = schwarz.jacobi architekts bda
Country = germany
Field of activity = architekture
Response = response_1
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Date=30_August_2011 , 23h11
Family Name = Jacobi
First Name = Georg
Institute = BSO
Country = Switzerland
Field of activity = Musician
Response = response_1
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Date=30_August_2011 , 23h30
Family Name = Dr.Pechmann
First Name = Heidi
Institute = Arztpraxis
Country = Deutschland
Field of activity = Medizin
Response = response_1
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Date=30_August_2011 , 23h43
Family Name = Pechmann
First Name = Michael
Institute = Novalisgesellschaft
Country = 37351 Dingelstädt
Field of activity = Geodesy
Response = response_1
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Date=31_August_2011 , 01h23
Family Name = Killian
First Name = Gotthard
Institute = music-healing-space
Country = Australia
Field of activity = musician
Response = response_1
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Date=31_August_2011 , 02h30
Family Name = Wright
First Name = Frederick
Institute = Google
Country = USA
Field of activity = Software Engineering
Response = response_1
The effort to eliminate leap seconds seems to be the beast that won't die. At least the Julian calendar had the excuse that it was trying to do the right thing and merely wasn't accurate enough. Here the proposal is to knowingly break the correspondence between the time scale and the Earth, leaving it for future generations to clean up the mess when the error becomes sufficiently large.
Note that very few modern computer systems have difficulty with the much larger one-hour step adjustments of the local time scale that occur as Daylight Time goes on and off. This is not because local time has been eliminated or redefined, but because computer systems have learned not to expect local time to be a well-behaved time scale, while continuing to use it in appropriate contexts.
The only reason leap seconds pose problems is that the move away from local time didn't go quite far enough. The correct solution is to use TAI (or TAI-K) for internal timestamps, while converting to and from UTC and/or LT as needed. This is precisely what GPS does, including not only using TAI-K for internal purposes, but also tracking the UTC offset and thereby making current UTC available.
The use of UTC with leap seconds for NTP synchronization does pose a couple of difficulties, but both can be dealt with:
1) The parties involved need to agree on the timing of leap seconds, in order to avoid apparent glitches in the internal time scale, which should be a "smooth" leap-free time scale.
2) The last UTC second of a day in which a leap second occurs is ambiguous.
No room for the answers. :-)
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Date=31_August_2011 , 07h27
Family Name = Vogt
First Name = Jürgen
Institute = Freie Waldorfschule Kassel
Country = Germany
Field of activity = Teacher
Response = response_1
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Date=31_August_2011 , 08h10
Family Name = Taylor
First Name = David
Institute = SatSignal Software
Country = UK
Field of activity = Space-sciences
Response = response_1
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Date=31_August_2011 , 08h32
Family Name = Ziegler
First Name = Renatus
Institute = Verein für Krebsforschung
Country = Switzerland
Field of activity = research scientist, mathematician
Response = response_1
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Date=31_August_2011 , 08h58
Family Name = Seaton
First Name = Daniel
Institute = Royal Observatory of Belgium
Country = Belgium
Field of activity = Astronomy-Astrophysics Space-sciences
Response = response_1
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Date=31_August_2011 , 09h01
Family Name = Hart
First Name = Dave
Institute = ntp.org
Country = US
Field of activity = Software Developer maintaining ntpd
Response = response_1
Redefining technical terms is the wrong way to tackle the perceived problem(s).
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Date=31_August_2011 , 10h01
Family Name = Rang
First Name = Matthias
Institute = Research institute at the Goetheanum
Country = Switzerland
Field of activity = Optics
Response = response_1
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Date=31_August_2011 , 10h13
Family Name = Nicula
First Name = Bogdan
Institute = Royal Observatory of Belgium
Country = Belgium
Field of activity = Astronomy-Astrophysics Celestial-mechanics
Response = response_2
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Date=31_August_2011 , 10h29
Family Name = Hobbensiefken
First Name = Sönke
Institute = CERES
Country = South Africa
Field of activity = agriculture
Response = response_1
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Date=31_August_2011 , 10h37
Family Name = DANIELE
First Name = ANTONIO
Institute = ITALIAN INSTITUTE OF NAVIGATION
Country = ITALY
Field of activity = air navigation
Response = response_3
Thak you for having sent this questionnaire to all IAIN members.It has been a very good and appreciable initiative.
In Italian Institute of Navigation, after wide and long discussion, we agreed the UTC timing and TAI timing should be the same (as, it was before 1972).This sentence from the consideration that time measuring in hours, minutes, seconds and other fractions is a convention originally starting from measuring the position of the Sun in relation with the Earth surface due to its rotation.
From a practical point of view, there are no reasons to maintain two different timing scales just because of the yearly revealed difference in Earth rotation by the strong precision of the atomic clocks.
We see the problem by a practical approach that means: which use would be done of such a precise but different timing on respect of Earth surface positioning to the Sun every day?
And, which kind of use may we do in the next hundred or thousand years of a timing progressively diverging from the upper indicated position relationship between Earth and Sun?
And also to maintain the current definition of UTC including the leap second, always on a practice point of view, would be unsatisfactory, because it will become without any sgnificance as the years will pass.
The space here do not permit the complete exposure of our discussions, anyway, if you need more informations, we are ready to send them to you anytime.
Sincerely yours
Antonio Daniele
General Secretary of
Italian Institute of Navigation
via della Scrofa, 64
00186 ROMA - ITALY
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Date=31_August_2011 , 11h07
Family Name = Dr. Rose
First Name = Ernst
Institute = Freie Waldorfschule Graz OG
Country = Austria
Field of activity = biology; chemistry
Response = response_1
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Date=31_August_2011 , 12h27
Family Name = Ferrandiz
First Name = Jose M.
Institute = University of Alicante
Country = Spain
Field of activity = Celestial-mechanics Earth rotation, satellite dynamics
Response = response_1
I cannot appreciate no real advantage in changing the definition of UTC but a lot of associated problems and riks of computation flows together with a large overhead to prevent them.
Therefore my opinion is to keep UTC in present form. Of course new time definitions may be introduced, but not representing an alternative of UTC in the short term but with research purposes to avoid unuseful, costly changes
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Date=31_August_2011 , 12h30
Family Name = Schmit
First Name = Scott
Institute = N/A
Country = United States
Field of activity = Telecommunication Software development
Response = response_1
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Date=31_August_2011 , 12h57
Family Name = Steiner
First Name = Bernhard
Institute = Institut für Gegenwartsfragen
Country = Germany
Field of activity = Space-sciences
Response = response_1
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Date=31_August_2011 , 13h39
Family Name = Massey (on behalf of the RAS)
First Name = Robert
Institute = Royal Astronomical Society
Country = United Kingdom
Field of activity = Learned society
Response = response_3
a. If the definition is changed, then the name of UTC should also change. While the proposed re-definition will make only minor differences over the next few decades, it is a major conceptual change. It would decouple UTC from Earth rotation as represented by the UT1 timescale - and thereby break away from the original concept of universal time introduced by the IAU in 1925. We believe that it is poor practice to make changes that invalidate existing text books, especially at the conceptual level. Good practice demands a name change – to stimulate people to probe into definitions of terms.
b. Whatever is decided at the ITU-R meeting in January 2012, there needs to be an easily accessible source of information on current and historical values of dUT = UT1 – UTC (or whatever succeeds UTC). This is a fundamental requirement for anyone pointing observing systems at objects away from Earth, whether astronomers with telescopes or engineers tracking spacecraft. This information needs to be freely and easily available to all, including the amateur astronomical community. Until now, both amateur astronomers and professional scientists have relied on this and if the change is implemented, future generations should continue to have equivalent access.
c. In the UK there is also a specific political issue: the proposed re-definition would necessitate primary legislation to change the basis of UK legal time from GMT to the new system derived from UTC, something the British Government has been reluctant to do in the past.
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Date=31_August_2011 , 14h45
Family Name = Galvin
First Name = James
Institute = eList eXpress
Country = USA
Field of activity = Internet networking
Response = response_1
My network applications and services depend on the current UTC definition.
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Date=31_August_2011 , 14h46
Family Name = Soma
First Name = Mitsuru
Institute = Natl. Astron. Observatory of Japan
Country = Japan
Field of activity = Astronomy-Astrophysics
Response = response_1
We live with the Sun. If no leap seconds will be introduced, the time we use will diverge from the ideal one which is in harmony with the apparent position of the Sun, so in any case we will need to make some adjustment to the time in the future. If there is no rule for the adjustment, there will be serious confusion in the future.
When one calculates the times of past and future astronomical phenomena, such as solar eclipses, sunrise, sunset etc., we need the value of TT-UT1 (for precise calculations one also needs UT1-UTC, but for most cases it is not needed). If UTC diverges from UT1, we will always need both of TT-UT1 and UT1-UTC, which complicates such calculations, and I do not like that situation.
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Date=31_August_2011 , 14h58
Family Name = Parker
First Name = Terry
Institute = KCOM
Country = UK
Field of activity = Telecommunication
Response = response_1
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Date=31_August_2011 , 17h07
Family Name = schulthess-roozen
First Name = marjolein
Institute = ita wegmanklinik
Country = switserland
Field of activity = medicine
Response = response_1
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Date=31_August_2011 , 17h52
Family Name = Kirby
First Name = John
Institute = none
Country = USA
Field of activity = Telecommunication
Response = response_1
This change could have far reaching consequences that affect public safety and public services. Time changes will affect radio system configuration and end user service management, geographical positioning navigational aids, computer aided dispatch systems, SCADA systems, and event logging and recording systems.
In the event of severe solar weather, time changes could render systems such as navigational aids inaccurate or ineffective in helping to direct the delivery of emergency services, gaining and maintaining situational awareness, or coordinating with multiple agencies.
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Date=31_August_2011 , 20h54
Family Name = Malone
First Name = David
Institute = School of Mathematics, Trinity College D
Country = Ireland
Field of activity = Public NTP Server Operator
Response = response_1
We have not experienced any difficulties during leap seconds.
Legal time in Ireland still seems to depend on GMT and consequently I think there would be a preference here for keeping UTC close to historical definitions of GMT.
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Date=31_August_2011 , 21h37
Family Name = Cornec
First Name = Jean-Paul
Institute = Retired
Country = France
Field of activity = Astronomy-Astrophysics Telecommunication
Response = response_2
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Date=31_August_2011 , 21h47
Family Name = Drury
First Name = Luke
Institute = Dublin Institute for Advanced Studies
Country = Ireland
Field of activity = Astronomy-Astrophysics
Response = response_2
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Date=31_August_2011 , 23h34
Family Name = William
First Name = Thompson
Institute = NASA Goddard Space Flight Center
Country = USA
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=01_September_2011 , 09h44
Family Name = Gelinek
First Name = Christian
Institute = N/A
Country = Australia
Field of activity = Electronics
Response = response_1
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Date=01_September_2011 , 10h45
Family Name = Monstein
First Name = Christian
Institute = ETH Zurich
Country = Switzerland
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=01_September_2011 , 12h23
Family Name = Escapa
First Name = Alberto
Institute = University of Alicante
Country = Spain
Field of activity = Astronomy-Astrophysics Celestial-mechanics Space-sciences
Response = response_1
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Date=01_September_2011 , 12h55
Family Name = Gary
First Name = Dale
Institute = New Jersey Institute of Technology
Country = USA
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=01_September_2011 , 16h10
Family Name = Dominique
First Name = Marie
Institute = Royal Observatory of Belgium
Country = Belgium
Field of activity = Astronomy-Astrophysics
Response = response_3
I do not like the idea of having UTC increasingly diverging from UT1. Nevertheless, leap seconds considerably complicate the processing of data that must be accurately time-tagged. Confusion and mistakes are frequent. Although there is no perfect solution, I think that the situation would be simpler if time correction was applied on a deterministic date, and more rarely. I would be in favor of a correction applied, for example, on January 01 00:00 every 10 years. Or even better, to apply them on each Feb 29.
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Date=01_September_2011 , 16h16
Family Name = Parenti
First Name = Timothy
Institute = University of Pittsburgh
Country = United States of America
Field of activity = Student
Response = response_1
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Date=01_September_2011 , 16h18
Family Name = Gamby
First Name = Emmanuel
Institute = Belgian Institute for Space Aeronomy
Country = Belgium
Field of activity = computer science
Response = response_3
I do not like the idea of having UTC increasingly diverging from UT1, but I think that the offset between both could be bigger than one sec. In addition, leap seconds considerably complicate the timestamping of data. Although there is no perfect solution, I think that the situation would be simpler if time correction would be applied on a deterministic date: for instance, on Feb 29 every 10 years or so.
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Date=01_September_2011 , 17h55
Family Name = Pechmann
First Name = Johanna
Institute = Ridterapi Novalis
Country = Sverige
Field of activity = horseback ridning
Response = response_1
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Date=01_September_2011 , 22h19
Family Name = Allen
First Name = Steve
Institute = UCO/Lick Observatory
Country = USA
Field of activity = Astronomy-Astrophysics
Response = response_3
I appreciate the problems faced by systems which have to handle conflicting requirements under the current implementation of leap seconds. Nevertheless, the current problems with leap seconds are largely one of representation. A better representation can preserve the existing and traditional meaning of UTC as civil time while also alleviating the problems faced by software systems.
I have written a detailed description of an alternative to the draft revision of ITU-R Rec. 460. This alternative is truly a compromise. It makes use of an existing, deployed, and routinely-exercised mechanism. It also changes leap seconds into a form which is easily-testable by systems and engineers.
The description can be seen here
http://www.ucolick.org/~sla/leapsecs/right+gps.html
I urge that this scheme be presented for wide consideration.
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Date=02_September_2011 , 01h14
Family Name = Homeyer
First Name = Gernot
Institute = Dr.med.
Country = Germany
Field of activity = Astronomy-Astrophysics
Response = response_1
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Date=02_September_2011 , 03h45
Family Name = Tschannen
First Name = Ruth
Institute = Cascadia Society
Country = Canada
Field of activity = Eurythmist
Response = response_1
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Date=02_September_2011 , 13h47
Family Name = scott-stapleton
First Name = graham
Institute = british sundial society
Country = britain
Field of activity = Astronomy-Astrophysics
Response = response_1
To disconnect time keeping from the earth's rotation will be to render time an entirely theoretical entity. To discontinue leap seconds is, in the long term, as ill-advised as discontinuing leap days.
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Date=02_September_2011 , 19h53
Family Name = Fischer
First Name = Gwendolyn
Institute = Christian Community
Country = Germany
Field of activity = Telecommunication
Response = response_1
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Date=02_September_2011 , 20h46
Family Name = Stuart
First Name = Robin
Institute = .
Country = USA
Field of activity = Astronomy-Astrophysics
Response = response_1
Surely the mandate of UTC is to provide a measure that is closely aligned with the principal driver of civil activity, namely time of daylight hours and the position of the Sun in the sky. While it may be argued that the existence of time zones and artifical lighting make the leap second of relatively little practical importance, at least in the near term, the drift will evetually become unacceptable on time scales that will depend on the particular application. Celestial navigation will likely be amongst the first disciplines to be affected but I suspect that even casual sky watchers will find it profoundly disturbing to know that the time of sunrise on mid-summer's day will vary over time, they cannot reliably specify the date of earliest sunrise from their location and that sundials can no longer be relied upon.
As scientists we seek uniform operating principals wherever possible. It may be argued that modern life and time keeping is no longer regulated by the exact position the Sun in the sky. But since few of us sow and reap the same arguments apply to the Gregorian calendar. If we do away with leap seconds then we should also revert to the Julian calendar. Of course astronomers do make use of Julian date which is fine for the conduct of science but I think that few would attempt to inflict it on the public at large just for their own convenience. This is what is effectively what is being done with regard to UTC.
What a tragedy years from now when sundials no longer work and our hard won mastery over the clockwork of the universe can no longer be demonstrated and accessible to the common man.
Robin Stuart, D.Phil, D.Sc.
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Date=02_September_2011 , 23h01
Family Name = Miguel
First Name = Martinez-Falero del Pozo
Institute = Other
Country = Spain
Field of activity = Medical Doctor
Response = response_1
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Date=03_September_2011 , 02h04
Family Name = Mischanko
First Name = Edward
Institute = None
Country = USA
Field of activity = Time-laboratory
Response = response_1
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Date=03_September_2011 , 18h29
Family Name = Saltzwedel
First Name = Gerhard
Institute = Praxis für Allgemeinmedizin
Country = Germany
Field of activity = medicin
Response = response_1
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Date=04_September_2011 , 04h19
Family Name = Senturia
First Name = Philip
Institute = None
Country = United States
Field of activity = interested layperson
Response = response_1
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Date=04_September_2011 , 19h26
Family Name = Neuwirt
First Name = Rudolf
Institute = Institute for Geometry; TU Graz
Country = Austria
Field of activity = Mathematics and Geometry
Response = response_1
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Date=05_September_2011 , 04h37
Family Name = Excoffier
First Name = Denis
Institute = Ecole Normale Supérieure
Country = France
Field of activity = computer science
Response = response_3
UTC to be defined by IERS (or equivalent) instead of radio ticks.
abs(UTC - UT1) to be kept small (like currently)
TI-TAI is fixed
UTC-TI is an integer number of (SI) seconds, 0 at time of transition (2022, see torino/closure.pdf)
use the "right" branch in the zoneinfo database
rename the "leap second" posterior to 2022 into another name ("intercalary second" would not be my
preferred choice)
Now a question: if transition is to occur on 2022-01-01, is the last possible leap second
2021-12-31Z23:59:60 or 2021-12-30Z23:59:60 ?
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Date=05_September_2011 , 08h04
Family Name = Kozisek
First Name = Frantisek
Institute = National Institute of Public Health
Country = Czech Republic
Field of activity = Environmental Health
Response = response_1
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Date=05_September_2011 , 09h54
Family Name = VOLK
First Name = Gerhard
Institute = LVermGeo RP, Koblenz
Country = Germany
Field of activity = Geodesy
Response = response_1
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Date=05_September_2011 , 12h46
Family Name = Bos
First Name = Mara
Institute = none
Country = Netherlands
Field of activity = religion
Response = response_1
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Date=05_September_2011 , 22h34
Family Name = Schmidt
First Name = Thomas
Institute = Waldorf-School
Country = Germany
Field of activity = Astronomy-Astrophysics Teaching
Response = response_1
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Date=06_September_2011 , 10h38
Family Name = Arias
First Name = Elisa Felicitas
Institute = Bureau International des Poids et Mesure
Country = --
Field of activity = Astronomy-Astrophysics Celestial-mechanics time metrology
Response = response_2
UTC was defined in 1972 when UT1 which had limited ways of dissemination. Celestial navigation and astronomical observations were the most concerned applications.
The methods of dissemination of time, of information, the communications in the seventies were not significantly affected by intentional unpredictable discontinuities of UTC, and this remained the case until the advent of GNSS and the development of the various communication networks.
Different possible ways of accessing UT1 appeared, and scientists were able to improve the uncertainty of its prediction. Real-time predictions are calculated, and their dissemination through different networks is possible today; even we can think of a dissemination via satellite navigation messages.
Who is today using UTC because it represent a "unique" access to UT1? Who is using dUT1 as regularly published by the IERS? Celestial navigation is no more the case; astronomers can have rapid access to UT1 by its predictions.
The leap secons represent a nuisance for the modern applications requiring time synchronization. For avoiding the leap second, internal timescales are constucted (case of GNSS), offset of several integral seconds. Inconsistencies within a system using diferent references (with and without leap seconds) in different components have an impact in security.
UTC without leap seconds will increase its offset with respect to UT1, not significantly affecting human activities, but it will positively impact and enhance modern applications. The IERS will increase visibility, disseminating real-time UT1.
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Date=07_September_2011 , 04h01
Family Name = Erdi
First Name = Jacobi
Institute = N/A
Country = Canada
Field of activity = complementary Medicine
Response = response_1
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Date=07_September_2011 , 09h51
Family Name = Coll
First Name = Guillermo
Institute = Hydrographic Office
Country = Spain
Field of activity = Geodesy Nautical Chart production
Response = response_1
The Official Position of the Spanish Navy Hydrographic Office is to maintain the current definition of UTC which includes leap second.
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Date=07_September_2011 , 10h44
Family Name = Dr. med. Husemann
First Name = Armin
Institute = Eugen - Kolisko - Akademie
Country = Deutschland
Field of activity = Medicine
Response = response_1
The system of Husman Physiology is coordinated by several "Biorhythms" which depended all on the Earth rotation. Earth rotation, transformed in Sun - Light - intensity, is transfered via the eye and Melatonin - Response of the Epiphysis in the whole System of human biorhytms. So the connex of Biorhythms in man with Earth rotation is a result of evolution and in no concern arbitrary.
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Date=07_September_2011 , 10h58
Family Name = Kühl
First Name = Johannes
Institute = Science Section, Goetheanum
Country = Switzerland
Field of activity = phyics
Response = response_1
The system of human Physiology is coordinated by several "Biorhythms" which depended all on the Earth rotation. Earth rotation, transformed in Sun - Light - intensity, is transferred via the eye and Melatonin - Response of the Epiphysis in the whole System of human biorhythms. So the connex of Biorhythms in man with Earth rotation is a result of evolution and in no concern arbitrary.
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Date=07_September_2011 , 20h36
Family Name = BARLIER
First Name = FRANCOIS
Institute = Observatoire de la Côte d'azur
Country = FRANCE
Field of activity = Geodesy
Response = response_2
Today, it is extremely easy to forecast DUT1 (Internet and space navigation and telecommunication) . On the contrary, it will be extremely useful and more simple to have a uniform time for dynamical studies and ephemerides in space geodesy and space mechanics. I fully approved the position on the future status of UTC and UT1 adopted by the Bureau des longitudes in Paris in May 2007.
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Date=08_September_2011 , 10h08
Family Name = Bonnefond
First Name = Pascal
Institute = OCA-GéoAzur
Country = France
Field of activity = Celestial-mechanics Geodesy Space-sciences
Response = response_2
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Date=08_September_2011 , 15h49
Family Name = ACHKAR
First Name = Joseph
Institute = Observatoire de Paris
Country = France
Field of activity = Time-laboratory
Response = response_2
- As a scientist involved in the Time metrolgy, I prefer that UTC be redefined as a uniformly increasing atomic timescale without leap seconds and constantly offset from TAI.
- The UTC system with leap seconds was essentially introduced to give access to UT1 within the necessary approximation for astronomical navigation. This astronomical navigation has almost completely disappeared. For scientific applications, the use of an accuracy uniform timescale (atomic timescale) is required.
- It is sometimes said that the present form of UTC does not present any inconvenience and that users of continuous time are able to cope with leap seconds without encountering major problems. The low frequency of occurrence of leap seconds in the last few years might support this opinion. But the general behaviour is the increase of this frequency. Due to decadal fluctuations of the rotation of the Earth, this frequency may reach two leap seconds per year in a few years time. This will make the probability of omitting or of making errors non negligible.
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Date=08_September_2011 , 22h45
Family Name = McBurnett
First Name = Neal
Institute = Boulder Community Network
Country = US
Field of activity = Systems software
Response = response_1
The worst approach is to redefine UTC so that the basic meaning changes (i.e. no longer linked to rotation of the earth) without changing the name "UTC". This would fundamentally confuse the name, require endless clarifications for the rest of time, and be a huge waste.
For people that want a timescale without leap seconds, let them simply use TAI, or if really necessary some variation on TAI like GPS time.
If the goal is to redefine a legal notion of time, this should be undertaken by a different body than ITU-R, which has no remit to disassociate clock time from solar time. E.g. the United Nations, or individual countries.
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Date=09_September_2011 , 15h07
Family Name = Grob
First Name = Herbert
Institute = Freie Waldorfschule
Country = Germany
Field of activity = Education
Response = response_1
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Date=12_September_2011 , 18h13
Family Name = Gambis
First Name = Daniel
Institute = Observatoire de Paris
Country = France
Field of activity = Astronomy-Astrophysics Geodesy
Response = response_1
The present system is a good compromise between Earth rotation and atomic time scale. Leap seconds introductions could be a nuisance for some restricted scientific communities but the system works well. Arguments to change are not sufficient compared to the advantages of a coordinated UTC time scale linked to the earth rotation.
Few problems were reported after the 2009 leap second introduction.
The issue is not only scientific, all scientists are able to adapt to any definition of UTC. A majority of UTC users are not aware of the difference between UT1 and UTC. If the new definition is adopted, they should.. When the difference DUT1 increases, 30s, 10 min, 1 hour, a lot of problems will arise..
There are too many softwares with the assumption of UTC being coordinated with the earth rotation. The costs of change would be important. Unforeseen problems could happen.
Why having another timescale in addition to UT (GPS) parallel to TAI without leap seconds?
The idea of suppressing TAI and to entrust the task of deriving a new continuous UTC by BIPM does not solve anything unless UTC be operational.
The possible adoption of a continuous time UTC time scale with the introduction of leap hours putting off to future generations is much worst than the present system.
The ITU does not appear to be the correct international body to change the definition of the worldwide system of civil time.
There is no strong justification to adopt a time scale no longer related to the rotation of the Earth. In any case, more time should be needed to evaluate the consequences of such a change.
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Date=12_September_2011 , 18h20
Family Name = Moshuber
First Name = Jöran
Institute = private
Country = Austria
Field of activity = Medicin
Response = response_1
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Date=15_September_2011 , 11h28
Nom = Bizouard
Prenom = Christian
Institut = Observatoire de Paris
Pays = FRANCE
Domaine = Astronomy-Astrophysics Celestial-mechanics Geodesy Geophysics Space-sciences
Reponse = reponse_1
There is no practical requirement for changing the definition of UTC. If for some practical issues, continous time scale is required, one has already at hand UT GPS or TAI.
Moreover this definition appears to be recent (the 1970's) in light of the long astronomical tradition going back to Sumerian civilisation. The current UTC concept is the fruit of a long scientifing ripening, combining technological progress (atomic clock) and the natural, biological rythm, founded on the sucession of days and nights.
Changing a definition too often has the same effect as to permanently produce new laws without fundamental reason: few people will note it, and this will diminish its force.
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Date=15_September_2011 , 14h48
Nom = LEFEBVRE
Prenom = Pierre
Institut = None
Pays = France
Domaine = Astronomy-Astrophysics Not professionnally
Reponse = reponse_1
The proposal to remove leap seconds from UTC appears contradictory with the definition of UTC: if UTC is not synchronized with Earth's rotation (within a 1 second accuracy), why maintain it ?
What we will be the meaning and interest of UTC in a few decades, when it will be 34 seconds behing TAI but, say, 10 seconds ahead of UT1 ?
Should the proposal be adopted, I would recommended keeping only 2 time-scales:
- TAI (as base for civil time around the world), introducing a one-time 34 seconds shift in all clocks worldwide
- UT1 (for astronomical applications)
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Date=16_September_2011 , 00h54
Nom = Glaser
Prenom = Thorsten
Institut = MirSolutions
Pays = Germany
Domaine = Telecommunication computing
Reponse = reponse_3
I have a strong preference for the current system with leap seconds
and keeping UTC an integral offset to TAI aligned with the real
earth rotation. Computing systems have coped for decades, changing
things now will introduce more new breakage than can ever be saved
by changing systems. Astronomically, it’s the only thing that makes
any sense, too.
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Date=16_September_2011 , 21h19
Nom = Tobin
Prenom = William
Institut = (retired from University of Canterbury)
Pays = France
Domaine = Astronomy-Astrophysics
Reponse = reponse_1
If I was setting up UTC again, I would decouple it from the Earth's rotation, because it has the same flaw as the French revolutionary calendar, i.e. you cannot tell how many seconds there will be from now to the end of the decade, just as the Revolutionary Calendar could not tell you how many dates until some date several millennia hence.
But as presently defined, UTC is a standard, and so should not be changed lightly. The consequences on many pieces of hardware are far from clear...for example where UTC and UTC1 are hard-wired/programmed under the assumption that there can never be more than 1 second between them. Further UTC is specifically referred to in many countries' legislation.
If there is to be a redefinition, it *must certainly* be given a new name and not called UTC. In fact, what I'd say is that we should just jump 34 seconds and start using TAI for civil timekeeping (but I believe there is some flaw in this because TAI is not known in real time.) So something similar to TAI.
Finally, of course, with the spread of computer networks we are moving to a point where it would be appropriate to abandon time zones and have everyone use a common time wherever they are on the planet. Already this is what some of the banks do when I pay on-line with my credit card. Any change to UTC should be coordinated with a change to a common time everywhere on the planet.
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Date=18_September_2011 , 05h57
Nom = Gerstman
Prenom = Larry
Institut = Long Beach Schools
Pays = USA
Domaine = Astronomy-Astrophysics
Reponse = reponse_1
Sorry for my late response, but I only just found your questionnaire.
I feel that the current system of defining UTC and adding leap seconds when needed is ideal and accurate. Please do NOT abolish the current system which works well and is vital to astronomical calculations throughout the world. No other system is even adequate.
A proverb we live by, "If it ain't broke, then don't fix it."
Sincerely,
Larry Gerstman
Long Beach, NY USA
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Date=18_September_2011 , 13h57
Nom = Citro
Prenom = Gary
Institut = Elmont U.F.S.D.
Pays = USA
Domaine = Astronomy-Astrophysics
Reponse = reponse_1
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Date=18_September_2011 , 14h29
Nom = Kozma
Prenom = Michael
Institut = CUNY
Pays = USA
Domaine = Astronomy-Astrophysics Telecommunication
Reponse = reponse_1
The time scale approach was tried in the past using atomic oscillation frequencies. It quickly lost favor since it was impossible to remember the constants. The current definition is more than adequate.
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Date=23_September_2011 , 17h19
Nom = Coy
Prenom = Robert
Institut = -
Pays = UK
Domaine = Telecommunication Transportation
Reponse = reponse_1
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Date=25_September_2011 , 14h35
Nom = Dawson
Prenom = Hylton
Institut = Britsh Sundial Society
Pays = England
Domaine = Celestial-mechanics
Reponse = reponse_1
Leap seconds are as crucial for synchronising clock time to the daily rotation of the earth as leap days are for synchronising the calendar to the seasons. Please retain the current definition of UTC and the leap second
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Date=29_September_2011 , 20h47
Nom = Novosielski
Prenom = Gary
Institut = Fort Lee (NJ) Board of Education
Pays = US
Domaine = Education
Reponse = reponse_1
I believe that the current definition, which is useful to all persons as long as they do not require access to earth rotation time more precisely than the nearest second, will be useful to many more people than a definition that is permitted to drift to an undefined degree.
Those who require UT1 precision closer than one second presumably already have access to such a standard, but changing the definition would require many more people to arrange access to one.
UTC is currently far more widely available than UT1. It can be determined to sub-second precision over any internet and radio sources nearly anywhere. Changing its precision from sub-second to indeterminately sloppy is, in my view, unwarranted.
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Date=06_October_2011 , 11h55
Nom = Maltin.
Prenom = Michael
Institut = Navigation.
Pays = UK.
Domaine = surveying.
Reponse = reponse_1
The present system should remain. It is best suited for the purposes of Navigation.
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Date=07_October_2011 , 22h26
Nom = LEFEBVRE
Prenom = Christine
Institut = None
Pays = FRANCE
Domaine = Individual
Reponse = reponse_1
Personnally, I am satisfied with the current situation. I would be very disappointed to see the Earth's rotation totally absent from the usual time definition, after having been used by humanity for thousands of years to measure time.
If it is decided to redefine UTC as a constant offset from TAI, it should not be called UTC anymore:
- it will not be UT because not related to the Earth's rotation
- it will not be "Coordinated", because there will not be any coordination anymore between an atomic time and the Earth's rotation.
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Date=11_October_2011 , 12h45
Nom = Vultaggio
Prenom = Mario
Institut = Italian Institute of Navigation
Pays = Italy
Domaine = Astronomy-Astrophysics Celestial-mechanics
Reponse = reponse_1
We focus our attention on the consequences of possible changes in the definition of UTC from the navigation point of view.
Currently UTC timescale is constrained to Earth rotation, by the introduction of leap seconds such that the difference between UTC and UT1is maintained within 1 second.
GPS is currently the most common navigation system and its timescale is related to UTC; GPS time and UTC differ for an integer number of seconds (the leap seconds accumulated since the GPS turn on) and the difference between GPS and UTC(USNO) (the UTC maintained by US Naval Observatory) is continuously sent to users. A change in the UTC definition, omitting the leap seconds correction, would not affect directly the navigation performance with GPS; this change would only affect the time reference of navigation, not more linked to GMT (whose UTC is an approximation).
The main problem related to the proposed change to UTC definition is that the output time form GPS is not related to legal timescale with consequences for all the application based on GPS time dissemination. Similar problems are present also in the other satellite navigation systems as GLONASS and Galileo.
For these reasons the change to UTC is not recommended.
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