Bulletin C number 18

[IERS/CB]

                 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 at 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