What is Leap Second

Coordinated Universal Time (UTC) is the primary time standard accepted by all the countries to keep their clock accurate.

UTC (Coordinated Universal Time) is calculated using International Atomic Time (TAI) and Universal Time (UT1).

Since Atomic clocks are very highly precise, the International Atomic Time (TAI) and Universal Time (UT1) can differ after a long period of time. The rotation of the earth is not as precise when compared with the precision of atomic clock.

A leap second is applied to occasionally to correct the above-mentioned time difference. When the difference of time reaches 0.9 seconds, a leap second is applied. This is to match with the difference in precise atomic clock time and imprecise observed solar time UT1, mentioned above. A leap second is that one second adjustment of time. By applying leap second, we are effectively stopping our clocks to synchronize with earth’s actual rotation time.