Leap Seconds To Be Phased Out By 2035

Governments from around the world agreed to put an end to leap seconds at the General Conference on Weights and Measures (CGPM) in November 2022.

The CGPM is the supreme authority of the International Bureau of Weights and Measures (BIPM). The BIPM is an international organisation established by the Metre Convention, through which Member States act together on matters related to measurement science and measurement standards.

Leap seconds are added to coordinated universal time (UTC) to keep it aligned with astronomical time (UT1), compensating for variations in the Earth’s rotation. Twenty seven leap seconds have been added in total since they were introduced in 1972.

Previous leap seconds have been added due to the slowing of the Earth’s rotation, however, there is now evidence that the rotation is actually speeding up which would result in the removal of a leap second. This would be the first instance of a negative leap second.

Due to the complexity of adding time across distributed systems, each leap second causes technical issues such as outages and data losses in the data centre sector.

Justifying the decision, BIPM said the "introduction of leap seconds creates discontinuities that risk causing serious malfunctions in critical digital infrastructure". This digital infrastructure includes satellite navigation systems, telecommunications and energy transmission. 

To handle future time gaps, the BIPM recommends that a policy be formed for the adjustment of clocks but has not specified at what time gap this adjustment might be implemented.

The change will come into effect by 2035, with the possibility of leap seconds being phased out sooner, and has been lobbied for heavily by tech giants such as Amazon and Google. Russia, however, voted against the change. This is due to the incorporation of leap seconds into its GLONASS satellite navigation system, unlike other satellite navigation systems such as GPS and Galileo.