Last leap second: 31 December 2016	TAI - UTC: 37 s	Next leap second: Not scheduled
Leap second file Leap second web service

Latest C04 values for pole coordinates (x,y) and UT1 on 13 May 2025 at 0h UTC:

x= 98.15 mas y= 426.73mas UT1-UTC= 28.524 ms

For the latest 7-20 days and the prediction
IERS recommends the use of Bulletin A
provided by the IERS Rapid Service (USNO, Washington)

Missions of the EOP Product Centre of the International Earth Rotation and Reference Systems Service (IERS):

Collect through the world the time series of the Earth Orientation Parameters (EOP):

pole coordinates (x,y)
universal time (UT1-UTC, UT1-TAI) or length-of-day offset LOD
Celestial pole offsets (Dpsi, Deps)

Archive EOP and make them avaible through FTP/WEB
Analyse EOP and in particular monitor their consistencies with respect to the international terrestrial and celestial referene frames.
Compute combined standard solution for EOP: Bulletin B or IERS C04 solution (daily since 1962), and IERS C01 solution (0.05 year sampling since 1846)
Compute and make available DUT1 (Bulletin D) and leap second announcements (Bulletin C).

Applications

astrometry
geophysics
space geodesy
orbit determination
timing
positioning

For users interested in the rapid and predicted EOP, refer to Bulletin A provided by the IERS Rapid Service/Prediction Center located at USNO.

Staff

Dr. Christian Bizouard
Astronomer
Director of the EOP PC

Olivier Becker
    Technician
    WEB master, C04 solution,
    operational service

Dr. Sébastien Lambert
Astronomer
Numerical analysis

Jean-Yves Richard
    Engineer, retired
    Multitechnique Combination
    "GINS Dynamo"

Dr. Daniel Gambis
Astronomer, retired
Scientific adviser

Teddy Carlucci
Engineer
Computer manager

Our graphics or plots are designed thanks to php package JPGRAPH

	Contact
Director Dr. Christian Bizouard	IERS EOP PC Observatoire de Paris 61, avenue de l'Observatoire 75014 Paris/ FRANCE	Tel 00 33 (0)1 40 51 23 35