INTERNATIONAL EARTH ROTATION AND REFERENCE SYSTEMS SERVICE (IERS)


SERVICE INTERNATIONAL DE LA ROTATION TERRESTRE ET DES SYSTEMES DE REFERENCE


SERVICE DE LA ROTATION TERRESTRE
OBSERVATOIRE DE PARIS
61, Av. de l'Observatoire 75014 PARIS (France)
Tel.      : 33 (0) 1 40 51 22 26
FAX       : 33 (0) 1 40 51 22 91
e-mail    : services.iers@obspm.fr
http://hpiers.obspm.fr/eop-pc


Paris, 4 July 2005


Bulletin C 30


To authorities responsible
for the measurement and
distribution of time




UTC TIME STEP
on the 1st of January 2006




A positive leap second will be introduced at the end of December 2005.
The sequence of dates of the UTC second markers will be:


2005 December 31,     23h 59m 59s
2005 December 31,     23h 59m 60s
2006 January   1,      0h  0m  0s


The difference between UTC and the International Atomic Time TAI is:


from 1999 January 1, 0h UTC, to 2006 January 1  0h UTC  : UTC-TAI = - 32s
from 2006 January 1, 0h UTC, until further notice       : UTC-TAI = - 33s


Leap seconds can be introduced in UTC at the end of the months of December
or June, depending on the evolution of UT1-TAI. Bulletin C is mailed every
six months, either to announce a time step in UTC or to confirm that there
will be no time step at the next possible date.






Daniel GAMBIS
Head
Earth Orientation Center of IERS
Observatoire de Paris, France