Meta has proposed doing away with “leap seconds”, offering to support an industry effort to stop future use of the confusing and potentially dangerous practice.
A leap second is a measure used to counteract the prolonged slowdown of the Earth’s rotation (opens in new tab)caused by the constant melting and refreezing of ice sheets, and the imprecise nature of the observed solar time (UT1).
First introduced in 1972, the global time watchdog of the International Earth Rotation and Reference Systems Service (opens in new tab) occasionally chooses to add another second to an hour.
Why the move?
“As an industry, we run into problems when a leap second is introduced,” Meta production engineer Oleg Obleukhov and Meta research scientist Ahmad Byagowi wrote in a blog post. (opens in new tab). “And because it’s such a rare event, it destroys the community every time it happens”
“With a growing demand for clock precision across all industries, the leap second is now doing more damage than good, resulting in failures and outages.”
Meta also noted that the leap second can be confusing for computers.
In 2012, Reddit . experienced (opens in new tab) a huge disturbance by a leap second; making the very popular website inaccessible for 30 to 40 minutes.
The time change reportedly confused Reddit’s high-resolution timer (hrtimer), causing hyperactivity on the servers, blocking the machines’ CPUs.
It’s not just Reddit that has encountered problems due to the practice.
In 2017 Cloudflare posted a very detailed article (opens in new tab) about the impact of a leap second on their public DNS, claiming that the root cause of the bug that afflicted their DNS service was the belief that time cannot go back.
To combat these potentially catastrophic outages, major tech companies like Meta and Google have used a technique called smearing, which involves “smearing” the leap second over a longer period of time, or 17 hours in the case of Meta.
Not only Meta is very critical of the practice.
The International Telecommunication Union is debating whether or not to end leap seconds and will publish a report on the subject in 2023.
27 leap seconds have been added since 1972, and chances are that’s all we’ll ever see.
- Want to make the most of the seconds you already have? Check out our guide to the best time management apps