WASHINGTON — Already a leap year, 2016 will drag on a bit longer. International timekeepers are adding a leap second at year’s end.

Because Earth is slowing down a tad, occasionally timekeepers insert another second or two to match Earth’s rotation and the precise atomic clocks.

Timekeepers announced Wednesday that on Dec. 31, at 11:59 p.m. and 59 seconds Universal Time, (6:59 p.m. Eastern Time), the next second will become 11:59:60. The new year won’t start for another second.

This will be the first leap second since July 1, 2015.