Time is up: The leap second will be scrapped by 2035

21 Nov 2022

Image: © benedetti68/Stock.adobe.com

Member countries of BIPM voted to find an alternative to the leap second, noting the risk of ‘serious malfunctions’ it can cause for critical digital infrastructure.

The leap second is ticking closer to its end, as the organisation responsible for global timekeeping plans to ditch it by 2035.

The leap second is a time adjustment added to Coordinated Universal Time (UTC) in order to keep atomic clocks synchronised with astronomical time. Since the introduction of the leap second in 1972, UTC has been updated 27 times.

While the adjustment may seem insignificant for most people, it has become notorious over the years for affecting systems that rely on precise time adjustments.

In 2012, a leap second change caused Reddit to go offline and there were issues affecting Mozilla, LinkedIn, Yelp and BuzzFeed. At the start of 2017, a leap second issue at Cloudflare caused some of its customers’ servers to go offline.

In a recent resolution, the International Bureau of Weights and Measures (BIPM) – which is responsible for UTC – acknowledged that these time adjustments create the risk of “serious malfunctions” in critical digital infrastructure such as satellites, telecommunications and energy transmission systems.

At a recent conference, the 59 member countries of the BIPM passed a vote to stop adding leap seconds by 2035.

In an email to news agency AFP, the head of BIPM’s time department, Patrizia Tavella, said the “historic decision” would allow “a continuous flow of seconds without the discontinuities” that the current system causes.

An alternative way to keep UTC synchronised with astronomical time will need to be found. The International Committee for Weights and Measures has proposed that no leap second should be added for at least a century, which would cause UTC to be out of sync by around one minute, Nature reports.

The decision to scrap the leap second will likely be viewed as a win for various tech companies. Earlier this year, tech giants such as Meta and Google joined an industry action that called for the leap second to be scrapped due to the disruptions it can cause.

10 things you need to know direct to your inbox every weekday. Sign up for the Daily Brief, Silicon Republic’s digest of essential sci-tech news.

Leigh Mc Gowran is a journalist with Silicon Republic