Global Timekeepers Vote in Versailles to Abandon Leap Seconds

Key points

• BIPM delegates are meeting in Versailles, France, from October 12 to 15 to vote on ending the practice of adding leap seconds.
• Leap seconds have been inserted 27 times since 1972, with the last adjustment occurring at the end of 2016.
• Earth’s rotation has accelerated since 2020, raising the possibility of a 'negative' leap second, which would remove time rather than add it.
• The proposed replacement is a 'leap hour,' which would only be necessary if UTC drifts by 3,600 seconds, a scenario that could take over a millennium.
• The change would eliminate disruptions to computer systems that assume time moves forward in 60-second increments, such as those experienced by Cloudflare and Reddit.

Background

In 2022, the BIPM’s governing body decided to abandon leap seconds by 2035, but Earth’s recent acceleration in rotation forced a faster timeline. Our archive notes that this shift aims to reduce disruption to critical infrastructure while addressing rare edge cases in timekeeping. The current vote follows a 2022 decision to increase the maximum difference between UTC and Earth rotation, with the 2026 meeting serving as the final decision point for the new standard.

How outlets are covering it

StratNews Global and The Conversation emphasize the technical necessity of the change, highlighting that modern software often crashes when time moves backward. The Conversation notes that companies like Google and Meta already use 'smearing' to mitigate this, but the vote would make such workarounds obsolete. ABC News highlights the philosophical concern that disconnecting official time from Earth’s natural cycle may alienate some, though experts argue clocks are artificial constructs. The Financial Times frames the vote as a broader test of international collaboration, linking the leap second debate to the need for standardized time on the Moon, where time passes 57 microseconds faster per day due to gravitational differences. While StratNews and ABC focus on the immediate technical benefits, The Financial Times views the BIPM meeting as crucial for future space exploration and lunar navigation standards.

Why it matters

Abolishing leap seconds would stabilize global digital infrastructure, preventing outages in financial systems, GPS, and communication networks. It also sets the stage for a unified time standard for space exploration, ensuring that future lunar missions and potential Mars operations can rely on consistent timing without the complications of Earth-based rotational adjustments.

What to watch

The BIPM vote is expected to conclude by October 15, 2026. If the resolution passes, UTC may become a continuous time scale without abrupt leap seconds as early as May 20, 2027. The next major adjustment, a 'leap hour,' is not expected for over 1,000 years, effectively removing the need for frequent timekeeping interventions for the foreseeable future.