Global timekeepers vote to scrap the leap second to prevent Y2K-style outages

BIPM votes to retire the leap second

Global timekeeping is heading for one of its biggest changes in decades. According to The Verge, the International Bureau of Weights and Measures (BIPM) voted on Thursday to eliminate the leap second, the occasional one-second correction inserted into international time standards to keep them in step with the Earth's uneven rotation.

The decision takes effect on May 20th of next year, a date chosen to align with World Metrology Day. That is a significant acceleration of an existing plan: BIPM members had already agreed in 2022 to stop applying leap seconds no later than 2035, but the new vote pulls that deadline forward by roughly eight years.

Why the timeline moved up

The Verge reports an unusual driver behind the accelerated schedule. Shifts in the Earth's rotation mean timekeepers may soon need to do something that has never been attempted: subtract time from the clocks rather than add to it, in order to keep astronomical time and atomic time in agreement.

Because a negative adjustment has never been carried out, there are serious concerns that attempting one could destabilize critical infrastructure that depends on precise time synchronization. Retiring the leap second before that situation arises removes the risk entirely.

A track record of disruption

Those fears are grounded in experience. When leap seconds have been added in the past, platforms including Foursquare, Reddit, LinkedIn, and Yelp suffered outages, along with many other services. Major technology companies — Meta, Google, Microsoft, and Amazon — have all backed the push to scrap the mechanism, according to The Verge.

The goal of the change is to head off infrastructure failures similar to the Y2K bug scare: a seemingly small alteration in how time is represented, but one with the potential to cascade into widespread failures across software and cloud systems.

Leap hours take over

Once the leap second is retired, timekeepers will rely on a far more relaxed replacement: 'leap hours'. Rather than nudging clocks by single seconds, atomic and astronomical time will be allowed to drift apart gradually, with a full hour added only once the accumulated difference demands it — an event not expected for roughly 3,000 years.

Why it matters

For developers and operators, the end of the leap second removes a long-standing source of fragility in distributed systems. Modern software depends on accurate clock synchronization, and even a single-second adjustment has been enough to take major platforms offline in the past. A negative leap second — an untested operation — carried the risk of far broader, Y2K-style failures across the software and cloud stack.

The trade-off is that tracked time will slowly diverge from the Earth's actual rotation, with the gap addressed only once every few millennia. For anyone running servers, databases, or cloud services, the practical outcome is simpler: no more surprise adjustments to engineer around, and one less edge case lurking in time-handling code.