Extra second added to 2008
An extra second will be added to official clocks around the world at midnight on New Year's Eve.
Big Ben, whose bongs bring in the new year across the UK, will be adjusted and the BBC will add an extra 'pip' to mark the delayed start to the year.
The extra second is needed because the earth is gradually turning around more slowly than it used to.
But experts reckon the extra second is such a short amount of time that most people won't even notice it!
Twenty-three leap seconds have been introduced since 1972 to keep GMT - internationally defined time.