I discover that overnight on 31 December 2008, I aged by more than expected and in 2014 sometime I may do so again.
The time it takes the Earth to rotate (a day) is getting longer by about 0.002 seconds a day, as it is ever so gradually slowed done by the drag of the tides and the atmosphere. For years it’s not been precise enough to define a second as simply as an 86,400th of a day. It’s now 9,192,631,770 oscillations of a 133Cs atom at rest and at 0°K, as measured by ultra-accurate atomic clocks.
Since 1972, 25 leap seconds have been inserted in our time keeping to keep Universal Time in step with the atomic clocks—which is what happened at the last second before midnight, GMT, on 21 DEc 2008 on the advice of the International Earth Rotation and Reference Systems Service thus increasing my age by 0.0000000512% or 5.12*10-8%. Scandalous!