This is filed under science, but really it could be under "who gives a flying…". So according to the International Earth Rotation and Reference Systems Service (IERS), there is a new standard unto which time is measured, and right now, we have gained literally seconds of time. Leap Seconds, as they are coined, can be positive or negative.
This ranks right up there on the list with Daylight Savings Time. The only difference is, and it’s a big one, this chronological octane boost has a purpose – and serves a purpose. Unlike DST – which was ill conceived from its inception and should be forced to go the way of the Dodo.
Think of it this way:
The correct reason for leap seconds is because the small difference between the length of the SI day and the mean solar day (currently about 0.002 seconds) adds up every day on the clocks that continuously count them. Note that the actual rotational period varies on unpredictable factors such as tectonic motion and has to be observed rather than computed.
Anyway, kind of an interesting tid bit for those who wish to set their watches to match SI time or seems to be confused by UT1, GMT, SI and TAI – so many clocks – so little time.