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Tech industry lobbies to dump the leap second

Peter Griffin, Editor. 26 July 2022, 12:06 pm

In one of the more obscure lobbying efforts to be taken up by Big Tech, a movement is underway to have time-keeping authorities do away with the practice of occasionally adding a ‘leap second’ to sync clocks with the Earth's rotation.

Amazon, Meta, Microsoft and Google this week argued that the adding of a leap second can do more harm than good leading to internet outages that could become increasingly disruptive. 

Timekeeping authorities have added a leap second to the global clock known as International Atomic Time 27 times since 1972. Why exactly do they need to add a leap second from time to time?

“The rotation of the earth is gradually slowing due to tides created by the gravitational pull of the moon,” explains Tim Armstrong, the director of the Measurement Standards Laboratory at Callaghan Innovation.

Screenshot 2022-07-26 at 12.02.53 PM.png

Source: Meta

“This gradual slowing is around 1 second per 18 months, but varies according to the seasons and other changes in the earth such as movements within the core of the earth,” he adds.

The Measurement Standards Laboratory maintains two caesium clocks at its Gracefield campus, which along with around 450 other atomic clocks around the world are used to calculate Co-ordinated Univeral Time (UTC). The clocks at Gracefield have an accuracy of around 1 second per 3 million years.

Essentially, the leap second keeps UTC in line with solar time. When a leap second is added, technically, this is what it looks like:

Instead of 23:59:59 changing to 0:0:0 at midnight, an extra 23:59:60 is added before the clock flicks over to 0:0:0.

But Meta’s engineers argue that adding leap seconds isn’t needed because the rotation speed of Earth has changed very little in the past anyway. 

They claim in a blog post that the practice is mainly beneficial to the scientific community:

“This periodic adjustment mainly benefits scientists and astronomers as it allows them to observe celestial bodies using UTC for most purposes. If there were no UTC correction, then adjustments would have to be made to the legacy equipment and software that synchronize to UTC for astronomical observations.”

But the leap second can cause major problems for companies running digital infrastructure. Reddit had a 30 - 40 minute outage in 2012 thanks to the leap second, while Cloudflare was caught out by it in 2017. The tech companies argue that in future, if a second had to be subtracted to adjust UTC, they don’t know how the various computer systems running internet infrastructure around the world would react.

Two major timekeeping authorities, the US National Institute of Standards and Technology (NIST) and France’s Bureau International de Poids et Mesures (BIPM) agree with the tech companies that the leap second should be done away with, CNET reports.

Some tech companies have come up with ‘smearing’, a way to deal with the leap-second problem that involves slowing down or speeding up the clock that computers operate on.

But smearing can be complicated. Why now just do away with leap seconds entirely, the tech companies argue. Any change will require international consensus, which to date has been hard to achieve on the subject of abandoning leap seconds, partly due to the influence of government research institutions.


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