June 30, 2012 leap second increase
Coordinates the International Earth Rotation and Reference System Service (IERS)Announce In the June 30, 2012 at midnight to add a Leap seconds. Coordinated Universal Time when the sun every day and the average number of milliseconds of error exists when the error is accumulated to a certain time, in order to maintain the time agreed, IERS will decide whether to increase or decrease in a second.
The technical measures are called leap seconds, IERS choose June or December for the last day of last-minute leap second leap second or not. Such as increasing the second, the next second day recorded as 23:59:60 23:59:59, 00:00:00 and then the next day; reduce the second, jump to the next day from 23:59:58 of 00:00:00.