A major change will soon be made to global timekeeping that aims to prevent potential Y2K-like infrastructure failures. On Thursday, the International Bureau of Weights and Measures (BIPM) voted to eliminate the leap second, an ad hoc time adjustment that is occasionally added so that recorded time standards reflect the Earth’s actual (and inconsistent) rotation.
BIPM members previously agreed in 2022 to stop using leap seconds in 2035 or earlier, but this is now being accelerated to come into effect on May 20 next year, in line with World Metrology Day. There is an unprecedented reason to bring forward its retirement: changes in the Earth’s rotation could soon require timekeepers subtract time instead of adding it to keep astronomical time aligned with atomic time. This has never been attempted before and there are concerns that doing so could wreak havoc on critical infrastructure that relies on time synchronization.
Those fears are not unfounded given that Foursquare, Reddit, LinkedIn, Yelp and many other tech platforms have suffered outages in the past when leap seconds were added. Companies such as Meta, Google, Microsoft and Amazon have supported efforts to remove the system. Following the BIPM vote, timekeepers will switch to using “leap hours,” allowing atomic and astronomical time to gradually drift apart until a full hour needs to be added, which is not expected to happen for about 3,000 years.
