Our ability to measure time has become so good that we've run into a problem. The Earth isn't very accurate. Which is awkward. Leap Seconds are our current best effort to bridge the widening gap between Atomic Time and the actual rotation of the Earth. But the addition of a leap second causes no-end of headaches for technology systems that often prefer to ignore it. In this talk I'd like to trace the history of Leap Seconds, how we deal with them and the ongoing debate about their future.