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

nature.com

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

#241

Post by Epa095 »

throw0101a wrote: post #198
bewaretheirs wrote: post #119

Earlier quoted context omitted.

it's really just a tzdata update for the vast majority of computer systems. That package updates several times a year. Get the revised rule in there a decade in advance and you're golden.

> it's really just a tzdata update for the vast majority of computer systems. I don't think you understand how the tzdata works: the tzdata folks only update the contents after the civil authority for a region changes the law . So first you have to get all the law makers to update what the legal statues say and then you "just" update the computer systems. The latter is the 'easy' part, it's the former that's the coor…

Let them handle it in the future when it becomes an issue, in roughly 500 years (that's when the lack of leap seconds will sum up to roughly 30 min). If they still care about having the sun above London at exactly 12 (or whenever it is in ut1) they can handle it.

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

#243

Post by zokier »

brazzy wrote: post #156
zokier wrote: post #127

Earlier quoted context omitted.

I'm pretty sure UTC is monotonic too, its unix timestamps that really are the true mess

Wrong. The very topic of this discussion, leap seconds, are non-monotonic adjustments to UTC.

In what way are leap seconds non-monotonic in UTC?

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

#244

Post by agrajag »

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…

The rate of drift is so slow that people will never care.

Even over thousands of years when an hour of drift is accumulated there won’t be a manual adjustment - people will have just gotten used to different times of day having sunlight, with generations having been born and died with mean solar time happening at 11am.

Eventually the rotation of the earth may change enough that drift accumulates too quickly and leap time needs to be added, but that’s only going to be true thousands to tens of thousands of years in the future.

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

#245

Post by worik »

jimmaswell wrote: post #190
svara wrote: post #138

Earlier quoted context omitted.

The moral of the story is that laziness is a virtue. Think of all the time that could have been saved, had you had no plans like your partners ;)

Think of all the time that could be better appropriated than on fintech in general. Seems like such a waste of resources siccing a bunch of computers against each other in a zero sum game of stock arbitrage. I will admit some of the stuff tech comes out of it is cool on its own at least.

> Seems like such a waste of resources siccing a bunch of computers against each other in a zero sum game of stock arbitrage

Despite the useful service of price discovery (here are so many better ways) it is clear from the EMH that those computers are not doing arbitrage, they are front running trades.

Illegal. Criminal in USA (I think). But makes billions and billions for the already very rich. So that is why there is so much of it

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

#246

Post by blippage »

Well that didn't long, did it? It was introduced in 1972.

In years to come historians will be having a good old chortle about how we managed to come up with two times that were 37 seconds apart.

In retrospect, fiddling with computer clocks like that was bound to be a nightmare.

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

#247

Post by philwelch »

ars wrote: post #13

So we make things worse for humans in order to make it easier for computers? Yah, one second doesn't matter, but it builds up. This: "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." Shows that they are completely disconnect from human reality: "Science already doesn’t use local…

Solar noon, or the solar meridian, is the time of day in which the sun is highest in the sky. If our times were completely natural, solar noon would be at 12 PM exactly.

Today, the solar meridian in Madrid is at 12:59 PM, while the solar meridian in Belgrade is at 11:23 AM. This is because Madrid and Belgrade are within the same time zone, in order to more easily coordinate European commerce.

If that's an acceptable tradeoff, I don't really see the issue in drifting something on the order of dozens-to-hundreds of seconds per century.

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

#248

Post by worik »

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…

> Currently software has to be built to accommodate leap seconds

Plenty is not.

The Swift time type ignores them in its implementation. I filed an issue, and they said there were no plans to implement them.

Good choice it turns out.

Who would of thought that adding a second on random new year changeovers would be worse than letting clocks drift.

Me for one.

We can have a "leap hour" in a thousand years. Till then do we care, I do not, if the clocks and the sun drift very slowly apart from each other?

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

#249

Post by worik »

layer8 wrote: post #161
charcircuit wrote: post #79

Earlier quoted context omitted.

There has never been a negative leap second. >If we kick the can down the road such that eventually we'll need to add a leap minute The drift is not in a single direction. The total drift is not going to be significant for a very long time if ever.

The total drift is accelerating long term, because the tidal deceleration of Earth‘s rotation due to the moon is quadratic.

It will be an urgent crises in a century, a millennium...

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

#250

Post by bewaretheirs »

vlovich123 wrote: post #142
N19PEDL2 wrote: post #123

Earlier quoted context omitted.

Then let's skip the leap hour too: just let UTC and UT1 diverge up to 86400 seconds and compensate that by changing the time zones when needed. Then, when the drift reaches 86400 seconds, the clock times are aligned again. At this point we just need to re-align the dates too, and this can be done by skipping February 29 on a leap year (which should be quite easy to implement in software).

Is that practical? Drift is slow and takes 1 min per century. Let’s say you can live with 10 minutes of drift. That leaves minutes [10-50] which is 4 centuries vs minutes [50-10] where it’s fine which is 2 centuries. Also, if the problem were time zones, time zones already support non-whole hour shifts, so why not just apply the leap second into all time zones? The reason is that that isn’t what a leap second is. It’…

We actually live with about +/- 15 minutes of drift (of local solar noon vs. 12:00 local mean time) over the course of a year. See https://en.wikipedia.org/wiki/Equation_of_time

And timezones one hour wide impose about a +/- 30 minute fixed error (and sometimes larger) on top of that - the difference between local mean time and local civil time.

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