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 2008
Bulletin C 36
To authorities responsible
for the measurement and
distribution of time
UTC TIME STEP
on the 1st of January 2009
A positive leap second will be introduced at the end of December 2008.
The sequence of dates of the UTC second markers will be:
2008 December 31, 23h 59m 59s
2008 December 31, 23h 59m 60s
2009 January 1, 0h 0m 0s
The difference between UTC and the International Atomic Time TAI is:
from 2006 January 1, 0h UTC, to 2009 January 1 0h UTC : UTC-TAI = - 33s
from 2009 January 1, 0h UTC, until further notice : UTC-TAI = - 34s
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