Do You Know Why An Extra Second Was Added To Indian Time?

A 'leap second' has been added to the Indian clock at 5:29.59 hours today to synchronize with the Earth's rotational clock. As the atomic clock at the National Physical Laboratory in New Delhi struck 23:59:59 last night, it was programmed to add an extra second to 2017 to compensate for a slowdown in the Earth's rotation.

The Earth and rotation around its own axis is not regular, as sometimes it speeds up and sometimes it slows down, due to various factors including earthquakes and moon's gravitational forces that often results in ocean tides. As a result, astronomical time (UT1) gradually falls out of sync with atomic time (UTC), and as and when the difference between UTC and UT1 approaches 0.9 seconds, a leap second is added to UTC through atomic clocks worldwide.

To be in sync with the Indian Standard Time (IST) and the Earth'ss rotational clock, the Indian clock needs to be adjusted after the insertion of a leap second.The leap second adjustment is not so relevant for normal everyday life. However, this shift is critical for applications requiring of time accuracies in the nanosecond, which are critical in the fields of astronomy, satellite navigation, communication networks.

Since 1972, 36 leap seconds have been added at intervals varying from six months to seven years and this will be 37th year.