NASA has reported that June 30, 2015, will be longer than all other days by one extra second.
The extra second, also known as the ‘leap’ second will be added to the original 24 hours in a day.
A day consists of roughly 86,400 seconds. This is the statistic that we use to measure a day, and the measure by which we live our lives daily. This is also called as UTC or Coordinated Universal Time.
The UTC, also known as atomic time, is the duration of one second, based on the electromagnetic transitions in the atoms of Cesium, which are rather predictable.
The cesium clock makes very reliable transitions. The accuracy of this clock is one second in 1,400,000 years.
A day, on the other hand, is based on the time taken by the Earth to complete one full rotation on its axis, which is 86, 400.002 seconds long.
As per the estimation made by scientists, since 1820, the mean solar day has not been exactly 86,400 seconds.
June 30 will see the addition of the leap second at precisely 11:59:59 UTC. This means that before it becomes July 1, 00:00:00, the atomic clocks will read June 30, 11:59:60 UTC.
The culmination of 0.002 over the years makes some days last for 86,401 seconds rather than 86,400 seconds. Another explanation is that the atomic clocks and the Earth’s rotation might be out of sync.
Had it not been for the addition of this extra second, the UTC which is measured by atomic clocks and the Earth’s rotation could become so out of sync over the years that midday is indicated by noon.