Move to end leap seconds

One thing that is integral to man's life on earth is time, or the measurement of it.

Time was long measured using the sun with a mean solar day being 24 hours. That was good enough then, although a solar day was not highly accurate due to variations in the earth's rotation.

That changed in 1955 when an atomic clock was developed that measured the vibration of an atom of caesium, leading to the adoption of International Atomic Time.

However this resulted over decades in differences between Atomic Time and solar based Universal Time and since 1972 it has been the practice to periodically re-synchronise them, by way of inserting a leap second.

The Earth's rotation rate is unpredictable more than six months in advance, so these leap seconds are added either at the end of June, or December. The last leap second occurred in 2005.

However there's an effort underway to consider getting rid of leap seconds and replacing them with a leap hour, or simply let the time variation accumulate to 60 minutes.

The world's time-keepers and time-users are debating the pros and cons of a United States proposal for a leap hour that is before an ITU-R Study Group.

Whether we switch from making leap second changes, to hourly changes that would be needed once every century or so, only 'time' will tell.

Jim Linton VK3PC
Wireless Institute of Australia