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 24 May 2024 at 0h UTC:

x= 26.94 mas   y= 437.55mas   UT1-UTC= -21.123 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)

    These time series are derived from the various astro-geodetic techniques (LLR, SLR, GPS, VLBI and DORIS).

  • 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).

  • 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.


Dr. Christian Bizouard
    Director of the EOP PC

Olivier Becker
    WEB master, C04 solution,
    operational service

Jean-Yves Richard
Multitechnique Combination
    "GINS Dynamo"

Dr. Daniel Gambis
    Astronomer, scientific adviser,

Dr. Sébastien Lambert
Numerical analysis

Teddy Carlucci
Computer manager

Pascale Baudoin
    Administration of EOP-PC

Our graphics or plots are designed thanks to php package JPGRAPH

Dr. Christian Bizouard

Observatoire de Paris
61, avenue de l'Observatoire
75014 Paris/ FRANCE
00 33 (0)1 40 51 23 35