On June 30 we get to sleep 1 second more...

...and the clock will count to 2012-06-30 23:59:60 to resynchronize the clock to Earth's rotation.

ftp://hpiers.obspm.fr/iers/bul/bulc/bulletinc.dat

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, 5 January 2012

                                              Bulletin C 43

                                              To authorities responsible 
                                              for the measurement and 
                                              distribution of time


                                   UTC TIME STEP
                            on the 1st of July 2012
                      

 A positive leap second will be introduced at the end of June 2012.
 The sequence of dates of the UTC second markers will be:  
  
                          2012 June 30,     23h 59m 59s
                          2012 June 30,     23h 59m 60s
                          2012 July  1,      0h  0m  0s
              
 The difference between UTC and the International Atomic Time TAI is:

  from 2009 January 1, 0h UTC, to 2012 July 1  0h UTC  : UTC-TAI = - 34s
  from 2012 July 1,    0h UTC, until further notice    : UTC-TAI = - 35s 
  
 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