VIDEO: Why your New Year’s Eve countdown will be longer than normal

An extra second added

An extra second added

This New Year’s Eve countdown will be longer than normal - but just by a second.

An extra second, or leap second, is being added on December 31 in order to keep the timescale based on atomic clocks in sync with time based on the Earth’s rotation.

The National Physical Laboratory (NPL), based in London, is introducing the 27th leap second to the UK’s timescale at just before midnight, meaning that the countdown to 2017 will be one second longer than normal, and time will officially read 23.59.60 instead of going from 23.59.59 to midnight.

Peter Whibberley, Senior Research Scientist in the Time & Frequency Group at NPL, said: “Atomic clocks are more than a million times better at keeping time than the rotation of the Earth, which fluctuates unpredictably.

“Leap seconds are needed to prevent civil time drifting away from Earth time. Although the drift is small – taking around a thousand years to accumulate a one-hour difference – if not corrected, it would eventually result in clocks showing midday before sunrise.”

However, the introduction of leap seconds is not without its problems.

Dr Leon Lobo, Strategic Business Development Manager for NPLTime®, said: “Because leap seconds are only introduced sporadically, they have to be manually programmed into computers and getting them wrong can cause loss of synchronisation in communication networks, financial systems and many other applications which rely on precise timing.”

So however you choose to spend your extra second, we hope you have a happy new year!