Leap Second 30 June 2012

This weekend sees the addition of a Leap Second onto world clocks, happening between 23:59:59 on Saturday 30 June and 00:00:00 on Sunday 1 July 2012. This helps keep our clocks in sync with the real world, since a day on Earth isn’t a regular 86400 seconds long every day. We used to measure time according to the spin of the Earth, but now we use far more accurate atomic clocks. These two methods of time keeping can drift, hence the need for the occasional leap second
Since 1972 25 leap seconds have been added. The last leap second was added at 23:59:59 on 31 December 2008. But leap seconds themselves are irregular, and are decided on by the International Telecommuntications Union whenever the two time signals drift by more than 0.9 seconds.
Enjoy your longer night’s sleep!