The gift of time is very precious. Only a supreme being can grant you additional time. Or, so it seems, so can the International Earth Rotation and Reference Systems Service. They are the organization responsible for deciding when to add, or subtract, a second to a day, traditionally December 31, to account for the slight slowing of the Earth’s rotation. These additional seconds are called leap seconds.
This year a leap second will be added on December 31. The last leap second event was on December 31, 2005.
The sequence of seconds goes like this:
2008 December 31, 23h 59m 59s
2008 December 31, 23h 59m 60s
2009 January 1, 0h 0m 0s
Notice that there is a second 60 in the sequence. This is the leap second. Normally you would roll over from second 59 to second 0 while advancing the minute. But you get an extra second in your day! 86,401 instead of the usual 86,400.
