International Bureau of Weights and Measures moves up leap second elimination to 2024
The BIPM voted to end the use of leap seconds on May 20, 2024, replacing them with a long-term “leap hour” system to avoid potential disruptions to time-dependent technology.
The International Bureau of Weights and Measures (BIPM) voted on Thursday to discontinue the leap second, an occasional adjustment added to keep atomic clocks aligned with Earth’s rotation. The change, originally slated for 2035, will now take effect on May 20, 2024, coinciding with World Metrology Day.
BIPM officials explained that future variations in Earth’s rotation could require subtracting time rather than adding it, a scenario that has never been attempted and could threaten systems that depend on precise time synchronization.
"The potential for a negative leap second raises serious concerns for critical infrastructure," a BIPM spokesperson said.
Past leap-second insertions have caused outages at platforms such as Foursquare, Reddit, LinkedIn and Yelp. Major technology companies, including Meta, Google, Microsoft and Amazon, have expressed support for eliminating the practice. Under the new approach, timekeepers will use a “leap hour” mechanism, allowing atomic and astronomical time to diverge gradually until an hour adjustment becomes necessary, an event projected to occur only after roughly 3,000 years.