Leap Second: The Extra Second

Our concept of time is based on the Earth's rotation, but did you know that the Earth's rotation is actually slowing down? At an incredibly slow rate of course - about 17 milliseconds per hundred years.

Still, it accumulates over time and as a result, every now and then we have to add an extra second to our clock to keep up with Earth's slowing pace.

This event is called a 'leap second'.

Since the system was implemented in 1972, leap seconds have been added 27 times.

That's 27 extra seconds we had that you probably didn't even know about.

Scientists add them either on June 30 or December 31.

Interestingly, the addition of these seconds can sometimes cause technical glitches in systems and networks around the world that are not prepared for the unexpected extra second..