Leap Second

The last minute of June 30th 2012 UTC will be 61 seconds long, the extra second being a "leap second".
Leap seconds are introduced to maintain synchronisation between atomic clocks and more traditional time scales such as Greenwich Mean Time. These leap seconds are introduced approximately every 18 months, at the end of June or December, usually to give the Earth's rotation a chance to catch up on our clocks. In Ireland the leap will take place close to 1am Irish Summer Time.
     

I will save my leap seconds up until i have a minute to spare ;}