Another Year for "CHANGE"

U.S. Naval Observatory is going to add a "leap second” to the world's clocks at 23 hours, 59 minutes and 59 seconds Coordinated Universal Time (UTC). That is rather than the usual 86,400 seconds in a day, the last day of the year will precisely have 86,401 seconds.

This marks the 24th leap second to be added to UTC, a uniform time-scale kept by atomic clocks around the world, since 1972. Leap seconds occur only at the end of a UTC month, and have only ever been inserted at the end of June 30 or December 31. It was last added on December 31st 2005.