The concept of the leap second is fascinating to me. Since our definition of a second isn't actually based on the length of a day (the time it takes for the Earth to rotate on its axis one time), rather the vibrations of a cesium atom, and since the gravitational energy transferred to the moon through tidal forces are slowly slowing the earth down, they've gotta throw a leap second in every once in a while. Most recently on June 30th, which apparently causes some computer servers to pee themselves a little.
It would be totally weird to see your clock go from 59 seconds to 60 seconds, then back to zero seconds instead of the usual 59 to 0 pattern. I might pee myself a little if I wasn't expecting it.
Kinda sad the moon is drifting away though. :(