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Leap Second

Coordinated Universal Time (UTC), the basis for our civil time, is occasionally adjusted by one second called leap second to insure that the difference between a uniform time scale defined by atomic clocks does not differ from the Earth's rotational time by more than 0.9 seconds.

Since the first leap second in 1972, all leap seconds have been positive.

historical list of leap second

Click here for the
historical list of leap second.

Last revision date: <20 Dec 2012>