[GJim]

> while UT1 is astronomically interesting, it's not actually a sensible basis for day to day living.

Hard disagree!

Allowing ones clocks to gradually drift from the behaviour of the Earth (which regulates our biological lives) is a mess. Once can compare the eventual correction that will be required akin to the shift from the Julian to Gregorian calendar and the problems that caused.

TAI was always there for those who needed it.

[zamadatix]

The drift (a second every ~1.5 years) is so small the accumulation is irrelevant to biological processes. 2000 years from now it does not matter that solar time has drifted ~an hour. Beyond "what people millennia ago used to do at 7 we do at when the clock says 8" not being a problem (assuming we even live similar lives) I'll be god damned if we can stop ourselves from changing zones and whether or not we'll observe DST this year for the next 20 years let alone what else we'll muck up in the next 2000.

TAI will still be there and needed by folks. UTC is stopping adding leap seconds in the future, not reverting back as if it never had any.

[throw0101d]

> The drift (a second every ~1.5 years) is so small the accumulation is irrelevant to biological processes.

It is irrelevant until it is not: just ask Julius Caesar and Pope Gregory XIII.

> Beyond "what people millennia ago used to do at 7 we do at when the clock says 8" not being a problem […]

The difference of an hour does make a difference, as sleep researchers and chronobiologists keep pointing out every time a discussion on DST comes up (it is not just about the sudden time jump, but also about the actual time):

* https://www.frontiersin.org/articles/10.3389/fphys.2019.0094...

* https://sleepresearchsociety.org/wp-content/uploads/2022/11/...

* https://srbr.org/wp-content/uploads/2018/10/SRBR-Statement-o...

* http://www.chronobiocanada.com/official-statements

[01HNNWZ0MV43FF]

If a difference of an hour that's been there your entire life is noticeable, we should be able to observe that as a discontinuity of quality of life at time zone boundaries.

[zamadatix]

> It is irrelevant until it is not: just ask Julius Caesar and Pope Gregory XIII.

You're refferring to needing to reform the entire calendar but this doesn't make sense in context of me explaining that the calendar itself never needs to be reformed in the first place. That the sun was a few degrees different in the sky for Julius Caesar when a modern clock reads 3 PM in his time is not inherently a problem as Julius Caesar wouldn't have the same norms as you do in terms of what wall time is acceptable for waking/sleeping/eating/working/etc. E.g. 20,000 years from now if a clock reads 3 AM during midday it' not a problem as society will have had 20,000 years to adjust 12 hours vs your referenced calendar reforms that changed everything overnight.

> The difference of an hour does make a difference, as sleep researchers and chronobiologists keep pointing out every time a discussion on DST comes up (it is not just about the sudden time jump, but also about the actual time):

Again, you're missing the forest through the trees - though in two different ways here. The first is that it's a minute over someone's (long) life, so what impact we feel when we change time by an hour twice a year isn't relevant. The second is that society, over 2,000 years, does not need to change timekeeping itself to wake up when the clock says 8 instead of 7. If the change were to happen over a short period then sure, it's not really feasible for society to move up what wall time their breakfast is four times a year or something, but an hour a millenia isn't even something society needs to consciously worry about.

My point is not that we don't have a biological clock, it's that the effect of leap seconds on a human's biological clock are too small to affect it. One of your sources already says it's 15-20 minutes misaligned a day, why are you using it to argue 1 additional minute for your entire life is impactful? On the long term societal scale my point is society won't always agree we should wake up when the wall clock says 7 am. That norm changing shifting ~an hour 2,000 years is not a relevant concern for changing the way we keep time.

[philwelch]

> The difference of an hour does make a difference, as sleep researchers and chronobiologists keep pointing out every time a discussion on DST comes up (it is not just about the sudden time jump, but also about the actual time)

Do any of these sleep researchers have anything to say about France using CET instead of GMT even though CET is about an hour off from their natural time? Or Spain being on CET despite being almost another hour off from France?

Furthermore, how long is it going to take for the accumulated leap seconds to add up to a full hour of time? My understanding is that it’s on the order of centuries. If humanity can maintain an industrialized civilization that’s capable of keeping track of leap seconds for that long, most of us won’t even be living on the earth by the time it makes any difference.

[throw0101d]

> Do any of these sleep researchers have anything to say about France […]

Perhaps ask French Sleep Research and Medicine Society (Société Française de Recherche et Médecine du Sommeil):

* https://www.sfrms-sommeil.org

* https://esrs.eu/national-sleep-society/france/

See also Spain:

> Human rhythmicity is subjected to the workings of the internal circadian clock, but it is also influenced by environmental time (mainly the light-dark cycle) and social timing imposed by the official time at our location, as well as by our work schedule. When a misalignment among these times occurs, an internal order impairment appears, which affects our health. Western Spain (GMT+1/+2) and Portugal (GMT0/+1) share similar longitudes (sun time) but have different official times, and thus they provide a “natural experiment” to assess how this discrepancy affects circadian rhythmicity and sleep in people with no work duties (>65 years). Although sleep duration was not affected, the circadian rhythms in the Portuguese were more robust, especially during weekdays, while higher desynchronization tended to occur in the Spaniards. Once official time was corrected by GMT0, meals took place later in Spain than in Portugal, especially as the day progressed, indicating the possible deleterious effect on circadian system robustness when official time is misaligned with its corresponding geographical time zone.

* https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9404853/

[zarzavat]

A leap minute every few centuries makes much more sense than a leap second every few years. We have until our great-great-grandchildren to prepare.

[throw0101d]

> A leap minute every few centuries makes much more sense than a leap second every few years. We have until our great-great-grandchildren to prepare.

People can't get the regular changes of DST and February 29 correct, and you want them to get a one-off change right?

I'd rather 'inflict' change (semi-)regularly so people at least try to get things right and get some practice, as opposed to a Hail Mary pass/change in some distance future.

[zarzavat]

We already have rules that are much rarer and more impactful than leap minutes would be. For example on Feb 29th 2000 an entire extra day was inserted on a century, an event that only happens once every 400 years! It was a complete non-event and only time nerds remember that it happened.

In the case of a leap minute, the worst that can happen is that your clock is 1 minute out every couple of centuries. Doesn’t seem so bad and certainly much better than dealing with leap seconds every few years.

We don’t need to constantly rehearse for such an event, we can just do nothing and die without worrying about it.

[Gare]

It was a non-event because 2100 will actually be an "odd" one, divisible by four but not a leap year.

Every dumb implementation that looked at division by 4 got 2000 right.

[lmm]

> People can't get the regular changes of DST and February 29 correct, and you want them to get a one-off change right?

Leap seconds are already rare enough that people can't handle them properly. Every time one happens the bug fixes from the last one have been undone.

[GJim]

That really is the motherload of technical debt.

This discussion really is highlining the cultural differences between software engineers and other engineering fields.

[zarzavat]

Not really. Adding leap seconds at the end of years is inferior because a year is a human-scale duration.

Planning something “next year” is human-scale. Planning something “next century” is not human-scale because I won’t be alive then.

If we use leap minutes then most people will not see one in their lifetime, compared to everyone seeing multiple leap seconds in their lifetime.

[ChrisSD]

But when that leap minute does eventually occur, it's going to cause havoc in all the systems that don't handle it. Which, let's face it, there are going to be a lot of. Either because they were never designed for it or else the relevant code paths were never actually tested.

[mminer237]

You could broadcast a leap minute with a decade to prepare for it and most software would still be developed, used, and die off in the 90 years in between. It's better for 15% of relevant software to have to worry about something so consequentially minor than 100%.

[scheme271]

That didn't work so well for y2k issues. Just this month there was an article about a woman that keeps getting id'ed as being 1 year old instead of 101 years old because of a y2k fix.

[marcosdumay]

If we are still using the same calendar in 60000 years, and if the Earth's Sun is still so important that we have to adjust our watches, we can start to talk about a leap day.

Granted, this is some 100 times longer than our calendar has lived. And some 10 times longer than any human calendar. So, I suggest we postpone the issue a bit.

[zarzavat]

Indeed, leap day, leap hour, leap minute, etc is a distinction without a difference because either way the solution is the same: do absolutely nothing and let future humanity decide how much drift it can tolerate.

[gavinhoward]

And yet, they won't, or won't be able to.

Leap seconds allow leap second bugs to be fixed in one generation. Leap minute bugs need cross-generational debugging.

https://gavinhoward.com/2023/02/make-the-leap-second-first-c...

[01HNNWZ0MV43FF]

Please no just let it drift