An Extra Leap Second will be Added to 2016 on December 31

The Leap Second How Does It Happen And Why Did New Year’s Day 2017 Start A Second Late

Saturday's leap second will be the 27th such insertion since 1972, with the last one added on June 30, 2015, and the 16th on a New Year's Eve.

The year 2017 is just around the corner, but you will have to wait a little longer before 2016 ends. While the leap second is necessary, the importance of timing signals means there can be issues if the adjustment is not properly implemented.

The NPL introduces them to ensure the time, which is based on the planet's rotation, does not lag behind the time kept by atomic clocks.

As 2016 has given the world an unprecedentedly contentious US Presidential election, claimed the lives of countless beloved public figures, and has generally cultivated turmoil throughout the world, most people tend to agree that they simply can not wait for the year to be over. The rotation of the Earth decelerates and is gradually slowing down.

Geoff Chester of the US Naval Observatory, part of the IERS, said: "The Moon raises tides on the Earth, and tidal bulges occur in the oceans".

The change is required because standard time lags behind atomic clocks. Because the rotation of Earth is not according to the accurate atomic clocks that time keepers usually utilize to tally each second.

2016 marked the 27th time a leap second was added since 1972
2016 marked the 27th time a leap second was added since 1972

As a result, every day, the rotation-based time loses between 1.5 and 2 milliseconds relative to the atomic clock.

This godforsaken extra second will be added during the midnight countdown to 2017 in UTC time, which translates to to 6:59:59 p.m. ET.

NPL, based in Teddington, London, is Britain's national measurement institute and the birthplace of atomic time.

Since 1972 until now, 26 seconds were added. And yet in its own way, "leap seconds" are much more trouble.

If leap seconds weren't added, the difference between astronomical time and atomic time in 1,000 years would be around 17 minutes. The move is similar to a leap year, wherein an extra day is added every four years to synchronize the calendar year (which is man made) with the solar year (which is determined by nature). But it has only been fairly recently in human history that we could measure time with such accuracy.

Precision clocks in the United States will add the extra second to the clock a bit before 7pm EST.