Leap Second Saturday June 30, 2012

CAPE CANAVERAL, Florida -- A leap second will be added on Saturday June 30, 2012 so that International Atomic Time will stay in sync with the the astronomical time of the Earth which is ever so slightly slowing its rotation.

The official bulletin was issued by the Earth Orientation Center of the International Earth Rotation and Reference Systems Service in Paris, France to atomic time keepers around the globe, inlcuding the U.S. Naval Observatory.

The last time a Leap Second was introduced was at the end of December 2008.

 

The instructions given for introduction of the 2012 June 30 Leap Second to time keepers are as follows:

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.