Global Officials Vote to Abolish Leap Seconds
Representatives from 69 nations decided to replace the practice with a leap hour adjustment system by 2027.
Updated on Oct. 20, 2026 in Space
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Should international timekeepers prioritize digital system stability over astronomical accuracy by ending leap seconds?
Officials at a conference in Versailles, France, have voted to abolish the use of leap seconds to synchronize clocks with Earth's rotation. The new policy, set to begin in May 2027, will instead utilize a leap hour adjustment once the time difference reaches 3,600 seconds.
Why it matters
Leap seconds have historically caused significant outages for global computing, telecommunications, and time-distribution services. Moving to an infrequent hour-long adjustment aims to eliminate the technical disturbances linked to previous smaller, more frequent corrections.
The new system allows the discrepancy between Coordinated Universal Time and Earth's rotation to reach 3,600 seconds before a correction. Previously, leap seconds were added whenever the difference exceeded a 0.9-second threshold.
The players
General Conference on Weights and Measures
This intergovernmental organization is responsible for maintaining the accuracy of global measurement standards.
The details
The decision marks a shift away from the practice of adding individual seconds, which last occurred in 2016. Timekeepers will now wait for cumulative discrepancies to build, with projections suggesting the first leap hour adjustment may not be required for several hundred to a thousand years.
Timeline
1958: International Atomic Time was introduced.
2012: The Linux kernel experienced outages due to a leap second adjustment.
2016: The last leap second was implemented.
October 15, 2026: An international body voted to abolish leap seconds.
May 2027: The abolition of leap seconds takes effect.
The Big Picture
The vote marks a fundamental change to the Coordinated Universal Time standard, effectively ending the practice of incremental second-based synchronization. This shifts the focus of timekeeping from constant micro-adjustments to a long-term model based on leap hour intervals.
This change reduces the risk of sudden system outages that have previously impacted data-logging and telecommunications networks during leap second adjustments. Most users will not notice the shift, as the adjustment to the base time system will only occur after several centuries.
The takeaway
The move to a 3,600-second adjustment system replaces a practice that created periodic technical risks for digital infrastructure. By prioritizing long-term stability over frequent synchronization, the international community aims to prevent future computer outages caused by sudden time shifts.
Further reading
Learn more about the latest developments in global timekeeping on the Space section.
Live Poll
Should international timekeepers prioritize digital system stability over astronomical accuracy by ending leap seconds?
