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The leap second’s time is up: world votes to stop pausing clocks

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Re: The leap second’s time is up: world votes to stop pausing clocks

#91

Post by e63f67dd-065b »

The full resolution can be found here https://www.bipm.org/documents/20126/64811223/Resolutions-20....

To quote the relevant section:

> [the CGPM] decides that the maximum value for the difference (UT1-UTC) will be increased in, or before, 2035

> [CGPM requests that the ITU] propose a new maximum value for the difference (UT1-UTC) that will ensure the continuity of UTC for at least a century

I think there are a few possible interpretations of this:

- We'll readjust UTC in a century (why would you do this to yourself, please no, nobody wants this) by setting a predicted maximum that'll last 100 years

- The maximum is now 1 hour, we'll adjust clocks the same way we adjust for DST

- The maximum is infinite, UTC is now TAI + the same integral offset forever

I'm hoping for the last one, but who knows. They've once again kicked the can down the road to the next 2026 meeting to decide what the increase in max UT1/UTC difference will look like.

Re: The leap second’s time is up: world votes to stop pausing clocks

#92

Post by schlowmo »

amflare wrote: post #34
clnq wrote: post #20

> Or we could even decouple our sense of time from the Sun entirely, to create a single world time zone in which different countries see the Sun overhead at different times of day or night. A very interesting idea, but probably much too progressive.

I mean, if chaos is the goal, then sure... Let me refer you to: https://qntm.org/abolish

> Do normal humans publish "waking hours"? Not typically.

I believe I just fell in love with that idea. If this would become a social norm people would maybe stop trying to reach me in the morning.

And I would know if it's too late to call others.

Re: The leap second’s time is up: world votes to stop pausing clocks

#93

Post by smilekzs »

spiderice wrote: post #86
techdragon wrote: post #80

Hot take… Storing anything as UTC was a mistake and we should be using TAI for all storage and computation, only transforming into more human friendly formats for display to end users. This never needed to be a problem except we decided to make it harder to use TAI than UTC and so everything got built up off the backs of legacy bios level hardware supported UTC style clock behaviour, when we should have been using TA…

What would using TAI solve exactly? I'm unfamiliar.

Datetime storage would consist of two explicit parts: one free from leap seconds (similar to the raw timestamp you get from a GPS receiver), and description of when leap seconds happen, so that you can transform the leap-second-free timestamp into UTC. Feels like a more robust way in principle to me.

Re: The leap second’s time is up: world votes to stop pausing clocks

#94

Post by ender341341 »

spiderice wrote: post #86
techdragon wrote: post #80

Hot take… Storing anything as UTC was a mistake and we should be using TAI for all storage and computation, only transforming into more human friendly formats for display to end users. This never needed to be a problem except we decided to make it harder to use TAI than UTC and so everything got built up off the backs of legacy bios level hardware supported UTC style clock behaviour, when we should have been using TA…

What would using TAI solve exactly? I'm unfamiliar.

TAI is monotonic clock, and isn't adjusted for solar time of day, it could be considered universal as TAI would be the same between any 2 points, but UTC is adjusted for earths rotation, so a theoretical mars UTC would end up out of sync with earth UTC.

EDIT: info below is incorrect about UTC not being monotonic, as pointed out in thread but is useful for monotonic vs non-monotonic:

In UTC you can jump forward or back, so it's possible to do an operation after another operation but have a timestamp before it, which is bad for many reasons, top being auditing.

do operation one at T0 do operation two at T1 do operation three at T-1

in TAI it would always be do operation one at T0 do operation two at T1 do operation three at T2

Re: The leap second’s time is up: world votes to stop pausing clocks

#95

Post by thfuran »

bombcar wrote: post #84
adamsb6 wrote: post #50

Currently software has to be built to accommodate leap seconds. They happen frequently enough that you'll find out within a few years whether your software breaks when time suddenly skips forward or backward. If we kick the can down the road such that eventually we'll need to add a leap minute, we're going to end up with software that was never written to expect time to change in such a way, hasn't had a real world t…

I've always thought that the best way would just have leap seconds every six months, and have it be ± 1 second no matter what - so sometimes you'd go back a second twice in a row, and then go forward a second to get back to correct. That'd test all the software paths.

Making time less accurate just for the sake of testing in production doesn't seem great.

Re: The leap second’s time is up: world votes to stop pausing clocks

#96

Post by cactus2093 »

bombcar wrote: post #84
adamsb6 wrote: post #50

Currently software has to be built to accommodate leap seconds. They happen frequently enough that you'll find out within a few years whether your software breaks when time suddenly skips forward or backward. If we kick the can down the road such that eventually we'll need to add a leap minute, we're going to end up with software that was never written to expect time to change in such a way, hasn't had a real world t…

I've always thought that the best way would just have leap seconds every six months, and have it be ± 1 second no matter what - so sometimes you'd go back a second twice in a row, and then go forward a second to get back to correct. That'd test all the software paths.

> That'd test all the software paths.

The daylight savings time bugs I've run into at pretty much every company I've ever worked at would beg to differ.

Re: The leap second’s time is up: world votes to stop pausing clocks

#97

Post by finnh »

> The CGPM — which also oversees the international system of units (SI) — has proposed that no leap second should be added for at least a century, allowing UT1 and UTC to slide out of sync by about 1 minute.

So, in one century, we'll get 1 minute's worth of drift.

Recall that we all share the same clock within timezones, and 1 minute of drift between atomic & solar clocks is the equivalent of traveling 1/60th of your timezone's width to the east or west ... something many people do every day as part of their commute. _Everyone's_ clock deviates from their local solar noon, and _nobody cares_.

Put another way: (at most) one north-south line in your timezone will have solar noon & clock noon line up. Over time the relative location of that line will move. Fine. Let's not screw with our clocks in an effort to keep the location of that line fixed.

Re: The leap second’s time is up: world votes to stop pausing clocks

#100

Post by rightbyte »

ender341341 wrote: post #89
jylam wrote: post #59

It seems I've got an unpopular opinion reading the comments here, but having some leap seconds from time to time ensure we are able to manage them. But "no leap second should be added for at least a century" ensures there will be a y2k reckoning every century. Seems short sighted to me, even if it is not a game-changing issue, let's be honest.

Why have them at all? how many people do things where they actually matter? at the current rate it'll be ~9000ad before we hit an hour offset, and we do hour offsets twice a year, so if an hour off is okay why is 1 second off not?

Ok let future generations take the hit. Got ya. Selfish ...
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