Big Ben
© PA
With the economic slowdown, 2008 may feel as if it will never end. Now the world's timekeepers are making it even longer by adding a leap second to the last day of the year.

Along with the economy, the Earth itself is slowing down due to the tug of the Sun and Moon, requiring timekeepers to alter their atomic clocks to keep in sync.

So an extra second will be tacked on to December 31 just before midnight, making 2008 - already long with the extra day in February - the longest year since 1992, which also had both a leap day and leap second.

The decision was made by an international consortium of timekeepers, whose American arm announced it yesterday. Most mobile phone providers and computer operating systems check with atomic clocks and update their time automatically.

The International Earth Rotation and Reference Systems Service started adding leap seconds to some years from 1972. They work to keep atomic clocks less than 0.9 seconds out of sync with Universal Time - the measure of time obtained from the rotation of the earth.