Time just changed forever

Time is getting a rewrite. For more than 50 years, the keepers of Coordinated Universal Time have quietly inserted extra seconds — leap seconds — into the world’s clocks, keeping hyper-accurate atomic time in step with Earth’s slightly irregular rotation. Since 1972, 27 such seconds have been added, the most recent on the final day of 2016. Now, Al Jazeera reports, the timekeepers have voted to stop — ending a half-century of tinkering with the second.

The decision is the payoff of a long debate in metrology. In November 2022, the General Conference on Weights and Measures voted to abolish the leap second by 2035, arguing the one-second jumps cause more problems than they solve: they crash software, scramble financial networks and tangle the precise timing systems behind GPS, aviation and telecoms. Meanwhile Earth itself appears to be speeding up slightly, raising the once-unthinkable prospect of a first-ever “negative” leap second.

Under the new approach, Coordinated Universal Time will be allowed to drift gently away from solar time, with the gap expected to stay under a minute for centuries. Scientists are developing new methods to reconcile atomic time with the planet’s rotation instead of the periodic fudge.

And the change reaches beyond Earth. With crewed missions returning to the Moon under NASA’s Artemis program, space agencies are building a lunar time standard — Coordinated Lunar Time — because clocks on the Moon tick about 58.7 microseconds faster each day than they do on Earth. As Al Jazeera’s Basel Ghazoghli puts it, the Moon is getting its own clock.

For the first time in half a century, humanity is redesigning how it counts the seconds — on Earth and off it.