From our other sites
The story
A resolution to effectively abolish leap seconds from May 2027, tolerating a drift from Earth’s rotation of up to one hour, is reportedly set to be reviewed at the General Conference on Weights and Measures in France this October.
In the thread, rather than the “one-hour drift” itself — which isn’t expected to occur for hundreds or even thousands of years — commenters focused more on the real-world struggles engineers have faced dealing with leap seconds, worries about the impact on GPS and missile-defense systems, and pointed remarks that this is ultimately just kicking the problem down the road.
Leap Seconds Effectively Abolished from 2027 — Rotation Drift Tolerated Up to “One Hour,” Vote at International Conference in October
A proposal to effectively abolish the “leap second,” which adjusts world standard time in one-second increments, will be reviewed at the General Conference on Weights and Measures (CGPM), to be held in France October 13–15.
Under the resolution from the International Bureau of Weights and Measures (BIPM), if adopted, the world will shift to a “continuous UTC” — one that makes no leap-second adjustments — starting May 20, 2027.
Source: itmedia.co.jp / Original article here
What people said
Saying 'I'll be dead by then anyway' feels pretty irresponsible though.
That's kind of terrifying.
Long live the slow life!
Should've capped it at a minute, at most.
I could never get along with people who're fine with daylight saving time.
If it were 10:10:60 instead, you could fudge things a lot more easily.
Nah, doesn't really change anything fundamental.
Car nav is one thing, but if military or mountaineering units get thrown off, isn't that dangerous?
Or is this kept separate from that, and it's purely about the time humans use?
Either way, that sounds like it'd get messy too.
It won't drift.
If anything, since every system implements leap-second insertion differently,
engineers have been coughing up blood trying to prevent drift caused by that — and now that's gone, so three cheers.
Marry me.
Leap years aren't adjusted case-by-case — under the Gregorian calendar, whether Feb 29 gets inserted in any given year is fixed far into the future.
It's a completely different concept.
if you count the fact that, for the first time on record, Earth's days have been shorter than 24 hours these past few years as 'outside pressure.'
But honestly, isn't this a good outcome? Better that only the industries that actually need to care about the UTC/UT1 gap have to deal with it,
rather than making everyone who touches a system clock worry about it.
Correcting it back would be rough too.
Can't be helped — the downsides outweighed the benefits.
Nobody wants system clocks getting fiddled with constantly these days,
let alone attempting, for the first time ever, a leap second adjustment in the reverse direction!
so by then old systems might have nobody left who can touch them — that could cause even bigger chaos.
If it were capped around a minute, you'd only adjust once every few decades, which still seems manageable.
How many systems even implement leap seconds these days?
Most just smear the drift via NTP now, don't they?
No such thing exists.
It's not something you can just work out with a simple calculation —
they just sync time based on announcements from international bodies.
Can system engineers really not foresee that?
Thousands of years from now, today's systems won't exist in any recognizable form.
There's no need to keep the current rule in place until the full one-hour drift actually shows up —
realistically this'll only ever amount to a difference of a few dozen seconds.
Fine to punt on this one.
Even after hundreds of years, it might only add up to a few minutes of drift,
and by then the timekeeping system will probably look totally different anyway.
Basically, the real question is what to do over just the next few decades —
and making every system scramble to handle unknown fallout over a UTC/UT1 gap that maxes out at a few dozen seconds is ridiculous.
Making every system implement negative leap seconds just for a few years' worth of a phenomenon is just terrible cost-benefit thinking.
I'd get chewed out by my boss for that.
it's not like they'll actually let the gap grow to a full hour before doing anything.
And the underlying definition of the 'second' itself will probably be replaced by some more precise method before too long anyway.
The world's clocks run on NTP these days —
this barely matters outside of stuff like rocket guidance systems.
Though the world will keep running on UTC regardless…
In a military context, lots of a nation's people could die, so think about missile interception here.
A junk system whose intercept timing is off by a whole hour is garbage.
Keep corrections down to one second — do your best.
That's the state's duty.
Protect human lives.
Wouldn't it be better if it happened at least once during a given engineer's working career?
Nobody said it's being left alone.
All that's been decided is that correction happens once the drift exceeds one hour.
In practice, 'correcting because it drifted an hour' will basically never occur —
by the time it drifts an hour, the systems involved will be fundamentally different anyway.
Background and Key Points
The leap second dates to 1972, when the world’s timekeepers grafted astronomical time (UT1, based on Earth’s rotation) onto atomic time (TAI) by letting UTC insert an occasional extra second, decided and announced by the International Earth Rotation and Reference Systems Service. Historically the Earth was slowing, so 27 leap seconds have been added, most recently in 2016. Japan’s own civil clock, JST, is maintained by NICT and simply follows these UTC announcements, meaning any change ripples straight into Japanese servers, broadcast systems, and telecoms without a separate domestic process. The proposal now before the CGPM would stop leap-second insertions from 2027 and only correct if the UTC/UT1 gap ever reaches a full hour — a threshold nobody expects to be reached for centuries.
The thread didn’t really argue about the one-hour number itself; posters broadly agreed that’s a non-issue. The actual disagreement was over whether abolition is a sensible fix or just deferred pain: some argued a small, decades-long drift is now impossible to correct gradually and will dump a much bigger, more chaotic adjustment on whatever engineers exist generations from now, while others countered that today’s systems won’t even resemble future ones, so pre-committing to a rigid schedule now is pointless.
What the thread glossed over is the actual trigger for this reform: for the first time since precise measurement began, Earth’s rotation has recently sped up rather than slowed, raising the unprecedented prospect of a negative leap second — subtracting a second, something no system has ever actually implemented or tested, which is far riskier than the insertions engineers are used to. Readers may also assume GPS timing itself drifts with leap seconds, but GPS time is a continuous count since 1980 that ignores them entirely; only the calendar display layer, not the satellites’ clocks, is affected.
*This article is compiled from excerpts and a summary of the 5ch (Science News+) thread “Leap Seconds Effectively Abolished from 2027 — Rotation Drift Tolerated Up to “One Hour,” Vote at International Conference in October.”
Leave a Reply