Google, Microsoft, Meta, and Amazon launched a public effort in July to eliminate leap seconds, the occasional extra tick that keeps clocks in sync with the actual rotation of the Earth. Timekeeping agencies in the United States and France agree.
Since 1972, the world timekeeping agency has added leap seconds 27 times to the global clock known as the International Atomic Time (TAI). Instead of changing midnight’s 23:59:59 to 0:0:0, it adds an extra 23:59:60. This causes a lot of computer indigestion, as computers rely on a network of precisely timed servers to schedule events and record the exact sequence of activities, such as adding data to a database.
Timing, they say, can cause more problems — like internet outages — than benefits. Dealing with leap seconds is ultimately futile, the team argues, because the Earth’s rotational speed hasn’t actually changed much throughout history.
“We predict that if we just stick to the observation that we should be at least 2,000 years old if we just stick to the observance,” Ahmad Byagowi, a research scientist at TAI Facebook’s parent company Meta, said via email. Maybe by then we might need to consider a correction. *
Tech giants and two major institutions agree that it’s time to ditch the leap second. They are the National Institute of Standards and Technology (NIST) and its French counterpart, the Bureau International de Poids et Mesures (BIPM).
This government support is critical because ultimately it is governments and scientists — not tech companies — that provide the support. Responsible for the world’s global clock system.
The leap second change caused a massive outage on Reddit in 2012, as well as related issues with Mozilla, LinkedIn, Yelp, and airline booking service Amadeus. In 2017, Cloudflare’s leap second failure took some of the network infrastructure company’s customer servers offline. Cloudflare’s software compares the two clocks and calculates the time backwards but cannot handle the result correctly.
Computers are really good at counting. But humans have introduced irregularities like leap seconds, which can work at work. One of the most notorious bugs was the Y2K bug, when a human-written database only recorded the last two digits of the year and screwed up the math when 1999 became 2000. A related problem arises in 2038, when some computers use 32-bit numbers that are not large enough to count seconds from January 1, 1970.
Earlier this year, when web browsers hit version 100, some sites blocked because they were programmed to only handle double digits version number.
To alleviate the problem that computer clocks don’t like 61-second minutes, Google pioneered “leap second smear,” which makes leap seconds change in many tiny steps throughout the day.
Adding leap seconds can cause problems with your computer. And at some point, we also have to subtract one – something that never happened – which may reveal new problems.
“It could have devastating effects on software that relies on timers or schedulers,” Byagowi and Meta engineer Oleg Obleukhov said in a blog post.