2008 will be just a second longer

Wait a second more before saying "Cheers to 2009!"

On December 31 midnight, you will have an extra second to usher in the New Year, because a “Leap Second” will be added to 2008 to let a lagging Earth catch up to super-accurate clocks.

Leap seconds are added to keep the atomic clocks synchronized with the Earth's rotation. This is because the Earth rotates at a slower pace over time while the atomic clocks do not slow down. Therefore, the leap second adjusts the clocks to ensure that civil time (used by clocks) is as close as possible to mean solar time (the mean sun’s hour angle).

The International Earth Rotation and Reference Systems Service is the organization that monitors the difference in the two timescales and calls for leap seconds to be inserted or removed when necessary.  Since 1972, leap seconds have been added at intervals varying from six months to seven years.

Leap seconds are inserted at the end of June or December as an additional second after 23:59:59 UTC (Universal Time Coordinated). The additional second is the 61st second of the last minute of the month, and it is written as 23:59:60 (or 11:59:60 PM in 12-hour format). This is the 24th leap second to be added since the first leap second was added in 1972. This is also the first leap second in three years. The most recent was inserted on Dec. 31, 2005.

That extra second will make 2008 — already long with an extra day on Feb 29 — the longest year since 1992.