Leap seconds face judgment day as time lords prepare to vote
International timekeeping authorities are considering a proposal to end the use of leap seconds by 2027. This change would allow Coordinated Universal Time to drift further from Earth's rotation to prevent technical errors in global digital infrastructure.
Why it matters
Eliminating leap seconds prevents potential system failures in critical infrastructure like power grids and telecommunications that struggle with irregular time adjustments.
Proposal would let UTC drift an hour from Earth's rotation, sparing computer systems awkward adjustments for centuries
It's about time: the General Conference on Weights and Measures looks set to end leap seconds in an effort to reach horological harmony.
Since 1972, 27 leap seconds have been added to Coordinated Universal Time (UTC) to keep it in step with the astronomical time scale UT1, which is based on Earth's fluctuating rotation.
The proposal would increase the permitted difference between UTC and UT1 from 0.9 seconds to one hour, avoiding leap-second adjustments for centuries.
Earth's rotation has also sped up in recent years, raising the possibility of a negative leap second – removing a second rather than adding one. That has never been done before.
Get smarter about the news
Sign up free for a feed built around what you actually care about, Dive Deeper research on any story, and the full text of every article.
Create free accountAlready have an account? Sign in