BBC – The New Year countdown is set to be momentarily delayed as a “leap second” is added to the final moments of 2016.
The second will be added to compensate for a slowdown in the Earth’s rotation and will occur as clocks strike midnight, when a time of 23:59:60 will be recorded.
The delay is needed as standard time lags behind atomic clocks which are used to provide a stable and coordinated universal time across the planet.
The International Earth Rotation and Reference Systems Service in France is responsible for tracking the Earth’s rotation and announces the need for a leap second.
Keeping time by the rotation of the Earth is unpredictable as rotations can fluctuate, while atomic clocks use the change in electron energy levels to tell the time, which is much more accurate.
The last time a leap second was added was in June last year. The New Year’s eve leap second will be the 27th time it has happened.
Peter Whibberley, a senior research scientist at the National Physical Laboratory (NPL), which is responsible for the UK’s national time scale, told the BBC: “Leap seconds are needed to prevent civil time drifting away from Earth time.
“Although the drift is small – taking around 1,000 years to accumulate a one-hour difference – if not corrected it would eventually result in clocks showing midday before sunrise.”
