On 15 October 2026, at the General Conference on Weights and Measures in Versailles, an international group of scientists, diplomats and timekeeping specialists voted to abolish leap seconds.
The decision was adopted by a majority of votes. From 20 May 2027, on Metrology Day, Coordinated Universal Time (UTC) will become continuous.
Instead of the usual one-second adjustments, a discrepancy between UTC and astronomical time UT1 of up to a whole hour will now be permitted. When the difference reaches 3600 seconds, a 'leap hour' will be added.
Since 1972, 27 leap seconds had been introduced to synchronise atomic clocks with the Earth's rotation. The planet's recent acceleration of rotation increased the risk of a negative leap second, which could have caused failures in digital systems.
Experts note that the first leap hour will most likely not be needed for at least a thousand years. This effectively removes the need for frequent adjustments for centuries to come.
"After 30 years of debate, we are ready," Noël Dimarcq, president of the Consultative Committee for Time and Frequency of the International Bureau of Weights and Measures, said before the vote.
The decision preserves the link between global time and the Earth's rotation, but makes UTC more stable for critical infrastructure — from telecommunications to energy and space.
Delegates from 69 countries supported the transition to rarer and larger adjustments. How will this affect the everyday perception of time in the long term?
The change will not affect familiar clocks and time zones. It concerns only the principle of reconciling the two systems of time measurement at the international level.
