Google, Microsoft, Meta and Amazon launched a public effort on Monday to eliminate the second leap, an occasional extra tick that keeps clocks in sync with the Earth’s actual rotation. The US and French timing authorities agree.
Since 1972, the world’s timing authorities have added a leap second 27 times to the global clock known as International Atomic Time (ITA). Instead of changing 23:59:59 to 0:0:0 at midnight, an extra 23:59:60 is included. This causes a lot of indigestion for computers, which rely on a network of precise timing servers to schedule events and to record the exact sequence of activities such as adding data to a database.
The temporary adjustment causes more problems, such as Internet outages, than benefits, they say. And ultimately dealing with leap seconds is pointless, the group argues, since the Earth’s rotation speed hasn’t changed much historically.
“We’re predicting that if we stick to the TAI without an intervening second observation, we should be good for at least 2,000 years,” research scientist Ahmad Byagowi of Facebook parent company Meta said by email. “Perhaps at this point we should consider a correction.*
Tech giants and two key agencies agree it’s time to ditch the second jump. These are the US National Institute of Standards and Technology (NIST) and its French equivalent, the Bureau International de Poids et Mesures (BIPM).
This government support is critical, since ultimately it is governments and scientists, not technology companies, who are in charge of the world’s global clock system.
The second leap change caused a massive Reddit outage in 2012, as well as related problems at Mozilla, LinkedIn, Yelp, and the airline reservation service Amadeus. In 2017, a second failure at Cloudflare took a fraction of the network infrastructure company’s customer servers offline. Cloudflare’s software, comparing two clocks, calculated that the time had gone backwards, but could not properly handle this result.
Computers are very good at counting. But humans introduce irregularities like leap seconds that can throw a spanner in the works. One of the most infamous was the year 2000 error, when human-authored databases only recorded the last two digits of the year and got the math wrong when 1999 became 2000. A A related problem will appear in 2038 when a 32-bit number used by some computers to count the seconds since January 1, 1970 is no longer large enough.
And earlier this year, some websites choked when web browsers hit version 100 because they were programmed to only deal with two-digit version numbers.
To alleviate problems with computer clocks that don’t like 61-second minutes, Google pioneered the idea of ”leap diffusion” which makes leap second changes very small over the course of a day.
Adding a dashed second causes problems with computers. And at some point, we’d also have to subtract one, which has never happened, and which would probably uncover new problems.
“It could have a devastating effect on software that relies on timers or schedulers,” Byagowi and Meta engineer Oleg Obleukhov said in a blog post on Monday.