In Paris, the International Bureau of Weights and Measures concluded that the leap second should be phased out, marking a historic shift in global timekeeping.
The vote followed five decades of debate, with 27 leap seconds added since 1972 and the last one inserted in 2016.
Dr Setnam Shemar, principal scientist at the UK’s National Physical Laboratory, said the move will cut risks to critical infrastructure while preserving the link between Coordinated Universal Time and Earth's rotation.
The leap second has triggered outages for firms such as LinkedIn, Reddit and Qantas in 2012, and engineers at Meta warned in 2022 that the added second was a major pain for hardware operators.
The replacement leap hour—scheduled for the final hour of June or December—will keep UTC aligned with the planet’s spin without the disruptive second.
The International Earth Rotation Service will announce the first leap hour in 2028 after a six‑month review, signalling a new era for precise global timing.