INTERNATIONAL EARTH ROTATION SERVICE (IERS)
SERVICE INTERNATIONAL DE LA ROTATION TERRESTRE


BUREAU CENTRAL DE L'IERS
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
Internet  : iers@obspm.fr


Paris, 12 Juillet 1999




Bulletin C 18


To authorities responsible for
the measurement and distribution
of time




INFORMATION ON UTC - TAI




No positive leap second will be introduced at the end of December 1999.
The difference between UTC and the International Atomic Time TAI is :


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


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
Director
Central Bureau of IERS