On New Year’s Eve, the National Physical Laboratory in London, the oldest timekeeper of the world will add one leap second to Greenwich Mean Time to take account of the slow spinning of Earth. It is an astronomical anomaly which causes a headache for timekeepers, but it is true, the Earth has gained 27 seconds since 1970.

If you want to bid adieu to 2016, you will have to wait a bit longer, one second to be accurate and the extra second will be added to align the clocks to Earth’s rotation. The second is being added to compensate the slowdown of Earth’s rotation. So the clocks instead of going from 23:59:00 to 00:00:00 will show briefly 23:59:60 before changing for the next day.

We know that the Earth takes 365 days 8 hours to make one rotation around the Sun. The 8 hours adds up and once in 3 years a leap day is added in February to compensate for the extra time. Something similar is done to make up for a delay in the spinning of the Earth on its axis. The leap second has become a regular feature since 1971 and a second is added once in two or three years. A leap second was added only last year in June.

Leap second is a headache for timekeepers, more so when a large part of the globe is becoming digital. It causes disruption in the reservation of airlines and financial sector. It has once lead to a massive interruption in the Russian GPS system.

Most timekeepers of the world use atomic clocks which are billion of times accurate. But the rotation of the Earth is being affected by some factors and not as perfect as the atomic clocks. Therefore amends have to be made in the atomic clocks by adding or subtracting seconds. Though the anomaly is very trivial, it will accumulate and become minutes and even an hour in the long run and could have the clocks showing midday when it is morning.