I once spotted a leap-second (belatedly - I'm not sad enough to sit in front of an atomic clock on New Year's Eve).

One of my Linux servers had been running for a couple of years and I happened to need to get onto the console, and there it was - notification that a leap second event had occurred and the time was 23:59:60

I am however sad enough to have taken a screen shot

Attachments
211.gif
Description: