[jwalton]

Another reason not to use EST/EDT is that they are overspecifying the time zone in most cases. If you ask for output in EDT, but the date is in December (which is not part of daylight savings time) then should the date output be UTC-4 or UTC-5? Technically you asked for EDT.

Using EST as a shortcut isn’t a good idea, either - most software will “know what you mean” and use EST or EDT appropriately... except, both The USA and Canada have been toying with the idea of dropping daylight savings time, so it’s very possible at some point in the future that 6:00pm on July 1st will be EDT in America/New York, but EST in America/Montreal (or vice versa). This is already true for CST - Saskatchewan doesn’t use DST. And there have been times where one country or another changes the start date or end date of DST too, so there’s no reason to assume those will always be the same between Canada and the US.

[Lvl999Noob]

On the topic of DST... can you explain why some countries use DST? Anytime I look for the reasoning of it, it says that DST helps "make better use of daytime" but how? The earth isn't gonna say "Damn! These people changed their clocks. I better change by rotation and give them more sun time." Whether you have DST or not, you still have the same amount of time with sunlight in a day.

[throw0101a]

The closer one is to the poles, the more the number of hours of daylight shifts over the seasons.

So at/near the equator, in a place like Panama, you will get roughly 12 hours of daylight in both the December and June Solstices.

* https://www.timeanddate.com/sun/panama/panama

Whereas in the Edinburgh you go from having 7 hours of daylight in December to over 17 hours in June:

* https://www.timeanddate.com/sun/uk/edinburgh

So people want those 7 hours to be when it's most convenient for them.

[asoneth]

The goal makes sense but our current DST implementation of a sixty-minute jump twice a year seems unnecessarily large and disruptive. (And not just dealing with kids -- traffic accidents and heart attacks spike after.) Whereas if there was a way to coordinate a daily shift it would be less than a minute.

It reminds me of when I'm camping. I usually fall into a dawn-based time system: Wake up around ~dawn, eat breakfast ~d+2h, lunch ~d+6h, dinner ~d+12h, bed down ~d+16h. You maximize daylight this way but the main problem is that you end up drifting relative to everyone else and if you want to rely on a standard watch to keep your schedule it requires some mental math.

I'd love to figure out how to use a combination of dawn-based time system for my daily routines plus UTC for remote collaboration.

[gumby]

It's a technology path dependence issue.

When towns had public mechanical clocks they were typically frequently adjusted (even daily) so that noon was when the sun was directly overhead.

Once railroads were developed their schedules were a mess since each time had to be in the time of the specific station. So the railroads got time zones introduced.

Then when the move for DST came around it had to be something easy to calculate, thus a one hour shift. Sort of like the Dow Jones: something that could be easily calculated by hand.

[AnIdiotOnTheNet]

The infuriating thing is that our solution to this is to change the clock instead of just changing our schedules. It's completely ridiculous.

[ceilingcorner]

...no, actually it’s extremely logical. Changing clocks society wide is far easier than getting every single person and company to adjust its schedule.

[fishywang]

>than getting every single person and company to adjust its schedule

but by using DST we are just pretending that we didn't ask people/companies to adjust their schedules. in reality they did, just the "clock" stayed the same.

[dhimes]

Exactly. Changing our clocks is changing our schedules, the easy way.

[kukx]

Yes, it is similar to how creating inflation by the government is just a way to tax poor and the middle class, without actually rising taxes.

[Lvl999Noob]

Perhaps it was easier in the times before the internet. Now a consistent timeline should be far more convenient than not having to change your habits by a little bit.

Edit: If changing schedule is normalized, then it would be just as convenient as changing the clock. In countries without DST, if someone started using DST instead of changing their own schedule, it would be just as difficult.

[ceilingcorner]

I don’t think anyone other than programmers thinks DST is much of an inconvenience. The clock changes twice a year, big deal. That’s infinitely less complicated than asking your boss if you can start earlier, which means the store at the subway station will need to be open an hour earlier (since its business comes from commuters), which means restaurants will need to be open earlier to address the lunch crowd, which means your doctor will need to schedule appointments earlier, on and on.

[remram]

Your argument sounds very similar to the "let's abolish timezones" argument so let me post this again: https://qntm.org/abolish

Changing your schedule works for you and your boss, but does not let people in other parts of the world know when they can reach you. Officially shifting something is necessary, and then you might as well have timezones.

[kjakm]

It's even easier post-internet. Your clocks automatically change for you now. In the past you had to remember when the change occurred and updated all your clocks manually - and if you forgot you ended up an hour late/early to any Sunday appointment after the change.

[exporectomy]

What's this inconvenience you're talking about? I often don't even realize when daylight savings changes because everything is automatic. My alarm wakes me up at the new correct time, the clocks on my phone and computer have adjusted themselves. Sometimes I wonder why the clock on the oven is wrong and then Google to find out that daylight savings just happened. Maybe some people have more dependence on non-internet-connected clocks or work through the night on Sunday?

[toomanybeersies]

Easier to get a few computers to automatically change their clock twice a year than every human being to change their schedule.

[asoneth]

This. Coordinating a mass schedule change is just an alternate implementation of a time shift.

The primary benefit of mass schedule change is that it might make (some) programmers' lives easier. The disadvantage is that it makes everyone else's lives harder as they adapt to schedule shifts.

(Clocks exist to serve people, people don't exist to serve clocks.)

[qwertox]

We shouldn't even adjust our schedules. We should just accept the fact that it is going to be dark at different times.

Then again, this would be an issue for road workers (those who repair highways or other roads) and maybe trash collection services. So it begins... Horrible.

[ljm]

Technically DST _is_ accepting that it's going to be dark at different times, and therefore the completely man-made thing that is a clock can be changed a bit to reflect that.

A perfectly human solution really: work around the shift in daylight hours across the year by fiddling with the clocks. The whole thing with schedules and timetables is a self inflicted problem in a post-industrial society, sure, but workarounds are never really meant to be more than a bandaid.

[ghaff]

The problem is that you need to "fiddle with the clocks" in a coordinated way. Schools can't shift around starting times asynchronously with the many businesses where parents work for example.

[rurban]

No, the worst is that date outputs wrong data without error. Wrong input is silently ignored, and the output 3 letter code is also wrong. Bug report pending

[hnick]

Times get written down or otherwise recorded, it would be a lot of work to update or duplicate entries for opening hours on signs and websites, times in laws, and various other things to account for the time of year. Instead we can just update the clock and have all the references preserved.

[wiredfool]

The worst thing is that the farther north you go, the less it matters. In Ireland, DST only really makes a difference for a month or so around the change. In the summer, light. In the winter, dark.

[ghaff]

DST mostly matters between about 35-50 degrees latitude. Less than that and the days are similar enough in length throughout the year that it doesn't really make sense to change clocks. And, as you say, much further north (or south) you have more light than you know what to do with in the summer and you're probably largely in darkness outside of work hours in the winter whatever fiddling you do.

[Dylan16807]

> So people want those 7 hours to be when it's most convenient for them.

In theory. Going by the normal justification for daylight savings, the convenient hours to have sun are the afternoon. But if that was it, then you'd expect the clock to be pushed even further in the winter.

[prerok]

It's actually the other way around. DST is applied in summer, so people actually want those 17 hours when it's convenient :)

[dreamcompiler]

..and the latitude where that 17 hours finally grows to 24 is called the Arctic Circle.

[mabbo]

Golf courses. Well, okay, this is my wonderful father's half serious answer that I love to retell.

The basic idea is that it's easier to convince everyone that is actually 5:00pm and time to leave work than it is to convince just your boss that you want to start work an hour earlier and leave and hour earlier.

This problem is then applied to politicians and other powerful people, who want to go golfing after work. If there's no DST, the sun will set "earlier" according to the clock, and you can't get in a full 18 holes.

So therefore, we change all the clocks so that powerful rich people can go golfing.

No other group of people sees any benefits to DST.

[gruez]

>So therefore, we change all the clocks so that powerful rich people can go golfing.

>No other group of people sees any benefits to DST.

Ah yes, because only powerful rich people would benefit from extra time in the evening to do outdoor activities.

[mabbo]

I didn't say it was right, just that I love it.

But truthfully, if our society wants more time in daylight after work... let's just leave work earlier. I mean, we are doing that, we're just changing the clocks and pretending we aren't. It's dumb.

[davidgh]

Since 2018, 13 states in the US passed resolutions to get rid of the semi-annual clock changes but also that daylight saving time become permanent. Of course, federal law doesn’t allow them to do such (a state only has the option to not observe DST, but not the option to permanently observe it).

It probably depends somewhat on latitude and longitude, I for one would prefer year round daylight saving time as I like the extra evening light in the summer and it’s dark when my kids leave for school in the winter anyway. I don’t golf.

The idea of shifting working hours to account for the season changes might work in some contexts but not others. Sure, if I’m an office “information worker” it’s probably not a big deal to shift to 7-4 in the summer. But I don’t think that’s going to work for retail, grocery, post office, restaurants, gyms, pharmacies, etc. where the public isn’t going want to constantly adjust to and guess at changing opening and closing times.

[mabbo]

But the public does adjust to changing opening and closing times.

We just all change the clocks as well and pretend that we didn't. And it's stupid.

[davidgh]

The previous discussion was talking about adjusting work hours as an alternative to daylight saving time. My comment is that’s not viable a alternative as I don’t think people want to try to determine if the post office closes at 4:00 or 5:00 depending on the date. Additionally, if everyone shifts working hours based on the time of year, how is that different than just changing the clock?

My point is not for or against daylight saving time, just that shifting work hours is not a viable alternative to it. And if we do get rid of changing clocks, there’s a decent chunk of the population that has expressed a preference for permanent daylight saving time rather than standard time.

It’s worth nothing that in Russia they experimented with permanent daylight time some years ago, and at first it was highly supported. However, after some years support for it dropped and they moved to permanent standard time. However, Russia deals with some unique geographical scenarios such as cities with extreme northern latitudes.

[creeble]

I don't know what you mean by "pretend we didn't". We don't pretend anything - we change the clocks and observe that change.

[jobigoud]

> a state only has the option to not observe DST, but not the option to permanently observe it

Do state have the option to change their timezone altogether?

Permanent DST is the same as shifting one tz over and not having DST and this would make more sense.

[Lvl999Noob]

Are there really places that don't observe DST and also don't change their working hours? Just shift the working hours by a few hours when the seasons change. It also gives more granularity for the changes. If 1 week in the whole season is particularly cold, then change the time again for that 1 week.

[majewsky]

That sounds like a huge coordination problem. Those problems are usually solved by some central entity enacting a standard, i.e. government enacting DST.

[Macha]

I assumed this was the norm in places that don't observe DST? Your workday is 9-5, year round, no we're not considering the time the sun sets

[CydeWeys]

> Are there really places that don't observe DST and also don't change their working hours?

Huh? I'll flip the question around on you: What places are there that don't observe DST that do change working hours seasonally, especially in a coordinated way? I haven't heard of any.

[TheRealSteel]

The liquor store I worked in in Australia had longer hours in summer than winter.

[CydeWeys]

Pools and parks have longer opening hours in summer than winter too. That's not really the same thing as DST though; it's orthogonal.

[happyopossum]

> Are there really places that don't observe DST and also don't change their working hours?

Yes, literally every state/province in North America that doesn't observe DST. I don't know what goes on in Europe, but nobody in Arizona for example changes the open/close time of their barbershop, restaurant, or gas station solely due to the time the sun rises...

[bombcar]

Even with DST here we still have "winter hours" for many businesses where it doesn't make sense to be open late (10 PM in summer is still light out, 10 PM in winter, sun set 5-6 hours ago).

[dmurray]

The golf courses are closed when it's too dark, but the offices aren't. You need to close the office a few hours before the golf course, even if your office business isn't strongly dependent on the amount of daylight.

[nerdponx]

Arizona

[SamBam]

Do Arizona banks and post offices and stuff really change their hours in different seasons?

[rwbcxrz]

Nope. There really isn't much reason to. The winters are mild, and Arizona is far enough south that there's still a good amount of daylight in the afternoons, at least compared to the northern parts of the US.

[GoblinSlayer]

Normally they match winter sunrise and keep it fixed all year long.

[BenjiWiebe]

I like DST and I'm neither rich nor a politician. I could be wrong, but I think farmers in general would be pro DST.

[mabbo]

Farmers are the most hurt by it.

Farmers need to work on daylight. They can't change their schedule when the clocks change. So during half the year, the busy half, all the business start closing down an hour early.

[xyzelement]

You got a bunch of longish replies to your question and I can't tell if they covered the simple answer. DST changes the question of : is it dark at 7am when I get up or not? is it light when I get off work at 5 or not?

It aims to shift the usable daylight hours to correspond with human activity.

[jolmg]

It's interesting how it's easier to change time than to change the hours in which we work. I wonder if there's any country where the government has enough control over working hours to shift those around instead. Instead of shifting the clock one hour, we could shift the time we start and end work.

It's like DST is the wrong solution to an XY problem.

Thinking practically though, DST is bound to work without enforcement, so it has that advantage.

[mikestew]

It's interesting how it's easier to change time than to change the hours in which we work.

What with covid/wfh, I have been wondering is this might be the push needed to end DST. Because I sure as hell have changed the time I work. Dog walk in the dark in December because about 4 hours of daylight in Seattle? Fuck that, we walk the dogs smack in the middle of the day now, we can work when it's dark. Strap on the reflective gear, headlamp, and go for a run? Oh, hell no. 2 in the afternoon, baby; I'll fix that bug late afternoon.

I still get up super early, but instead of getting in that run before work, I just work. Then shift that running time to when the sun's up. But I speak from the position of the privileged tech worker (and one w/o a lot of meetings). There are still the DST issues of when children stand waiting for the school bus, et. al.

[ben509]

> It's interesting how it's easier to change time than to change the hours in which we work.

I think the main pain point would be customers being confused as to when companies are open.

This doesn't even work well with smartphones; all the calendar apps are hopelessly manual and can't answer something like "what are good times to run an errand involving steps X, Y, Z."

At best, you can ask it when people are available for a meeting and it will show you that everyone important is booked solid.

[jolmg]

> I think the main pain point would be customers being confused as to when companies are open.

But why would so many people rely on a 1 hour difference that this would become a "main pain point"? I don't know the working hours of most places I go to. When I really want to know, I check Google Maps (or their website). Even then, when it's close to opening or closing hours by like an hour, I sometimes prefer not to trust it if it'd be too problematic for it to be closed after making the trip, because it does happen at times that it's incorrect. Small shops might not even follow their own stamped-on-the-window working hours strictly either.

[freeopinion]

I'd be interested to hear the experience of people in China. As I understand it, all of China shares a single timezone while neighbors to the north and south are spread across five timezones.

Clocks in western China are four hours out of sync with their neighbors just over the southern border in Pakistan, for example. So do businesses in western China open from 1pm to 9pm? Do people eat breakfast at noon?

I'm really curious about that experience.

[wahern]

https://www.theatlantic.com/china/archive/2013/11/china-only...

[filoleg]

I think one practicality of it that you forget is the difficulty for people too, not just for businesses or government entities.

For example, people are used to banks always being open 9am to 5pm. With the approach you mentioned, it means that twice a year they will have to shift it. It means you will also have to shift your entire schedule, and calendar, and literally everything. Now think about some shops and places that will NOT be switching it and decide to keep the same hours. Then add-in the fact that some shops already change their hours even with the current system. For example, I have a daily recurring alarm for 7am. Under this proposed system, I will have to manually change it twice a year (while now it is done automatically due to the entire timezone switching twice a year).

You will simply get a logistical nightmare, since changing the entire clock is much much simpler than shifting each individual little scheduled item in your life.

Tl;dr: while i agree that logically your approach of shifting individual scheduling items to align with the daylight hours makes more logical sense, it makes more practical sense to just switch timezones twice a year for that purpose.

[jolmg]

> I have a daily recurring alarm for 7am. Under this proposed system, I will have to manually change it twice a year (while now it is done automatically due to the entire timezone switching twice a year). You will simply get a logistical nightmare

At least with respect to updating the alarm, that "logistical nightmare" can't be any worse than what we had before clocks updated themselves. I still remember having to update all clocks manually twice a year. It wasn't a big deal. Someone coming in late or missing an appointment because they forgot to update a clock happened rarely. Maybe it's not the case now, but you used to get multiple warnings reminding you to update your clocks.

> For example, people are used to banks always being open 9am to 5pm. With the approach you mentioned, it means that twice a year they will have to shift it. It means you will also have to shift your entire schedule, and calendar, and literally everything.

With respect to opening and closing hours of banks and shops, for those few people that go near opening or closing hours even in that time of the year, they'll make the mistake that day and either come back later when it's open or otherwise fix their issue that day or at least they won't make the same mistake the next day. The world wouldn't go up in flames because of this.

[bjourne]

> It's interesting how it's easier to change time than to change the hours in which we work. I wonder if there's any country where the government has enough control over working hours to shift those around instead. Instead of shifting the clock one hour, we could shift the time we start and end work.

Iran used to do that. But for some reason they abandoned it and now use "normal" daylight saving time.

[davchana]

Indian offices, schools, shops do this. Although I don't think its by government order, it is just the it is always. Almost every timings psoster show winter/summer times.

[somehnguy]

>It aims to shift the usable daylight hours to correspond with human activity.

But it fails miserably at it.. Here in NYS all winter long it gets dark at 5PM. Summer, 9PM.

It's useless and just causes inevitable confusion every year.

[jws]

There’s nothing to be done about winter, that is the “regular” time and you live in the north. You only get the sun above the horizon for 9 hours a day in late December.

The summer 9pm is the advantage of daylight savings. You get the sun up for 15 hours a day! Norther summer is great. Without daylight savings time, you’d get dark at 8pm in the summer and have an hour of “wasted” daylight before you got up. The “savings” part is to take the wasted light while you are sleeping and move it to the evening when you can enjoy it.

It does cause confusion though, and having implemented daylight savings code there are a bewildering number of rules around the world, there are even places that have double daylight savings. They shift once, then shift again for a two hour offset.

[somehnguy]

I appreciate the response and explanation, I guess I was mistaken on which direction DST was being used for! All my life I was under the assumption that it was the other way around, to try and get back more time during the winter. Thinking about it more now though, that doesn't even make sense given the direction the clock changes..

I'm still not sure it is worth the confusion it causes but I do have a better understanding of why it exists now. Thank you!

[1strepublicusr]

I love the extra hour of daylight in summer evenings and anytime I'm anywhere where it gets darker early in the summer I feel like I'm giving up part of the fun of my life.

[fireattack]

I still don't get it. During the winter, the daylight hour is literally shorter, not just shifted. Shifting one hour won't magically make it longer. At best it gives your more daylight in one end, while sacrificing the other (and more than 1 hour, since again, the total daylight hour is shorter). So why bother?

[notJim]

Because the idea is that sunlight during a particular part of the day is more valuable. One reason I've seen given (not saying I agree with it) is that if you "move" the sunlight to the morning, it means kids won't have to wait for the school bus in the dark. Or if you "move" it to the afternoon, then there will be a little bit of daylight at the end of the day for people working 9-5, which might be useful if you want to go for a run or something.

[macintux]

Just once I’d like to have a time zone discussion on HN that doesn’t devolve into pages of arguing about daylight saving time.

If you search HN you’ll find plenty on this topic.

[db48x]

You'll have a happier life if your dreams are attainable.

[klyrs]

I mean, you're not wrong... but what else is there to talk about?

Fact of the matter is, your preferences depend on where you live, your lifestyle, and the amount of time you spend on date&time fuckery in code. It's a contentious issue.

[davchana]

I am from India, northern part, where there is a lotbof variation between sunlight hours throughout the year. Some days the sun is out at 6 or before in summer, & in winter its some time not out even till 9 or such.

India does not use timezones. Every business, school, office who has business hours, use something like Winter Timings Summer Timings. Schools & such use 14 Oct to 14 Apr as Winter, & other 6 months as summer. My school used to open at 6 in summers, & 7:30 or 8 in winters.

Here in US they keep the opening timings same throughout the year, but go through this DST shenanigans.

[XorNot]

For the same reason that work from home turns out to be viable for a huge number of people, and the main reason office's are as big as they are is because middle managers don't believe work happens if they don't watch someone sit in an office chair.

There's no possible way businesses are going to adjust their hours twice yearly to let employees get more sunshine, but DST does that effectively by ensuring official timekeeping gets moved about on them.

[bombcar]

The even dirtier secret is that NOBODY KNOWS if work is getting done because often the work is pointless or ill-defined.

[GoblinSlayer]

What is the point of sunshine if you sit in a box all day? You get equally zero amount of it during summer as well as winter.

[KineticLensman]

> Whether you have DST or not, you still have the same amount of time with sunlight in a day

Yes, but you can better align the available light with things like commutes and school hours - so that people commute in light instead of the dark, for example.

[snarf21]

We need to get rid of DST switches permanently. We should stick with DST as most people prefer extra light at night.

[BjoernKW]

Because of the unfortunately still common 9-to-5 work schedule.

[throwaway2245]

The excuse usually given is to match up farm work, which is dictated by dawn, with general work shift patterns.

However, I recall that farmers are very split on the issue when polled - it impacts on their work shifts as well.

[Arubis]

Source: none, this is my pure supposition and projection.

Power. The sensation of raw power.

By and large, the best way to eliminate DST would be for one or more sufficiently powerful lawmakers or political executives to say: this is no longer benefiting the public at large, and we are going to stop!

These are the folks empowered to change the date on which DST transitions (at least stateside). These are also the same folks whose careers have been mostly defined by the deliberate and incremental accumulation of power into their own hands.

If you're wired for that kind of desire for power, the ability to tell the entire country: okay, I am changing time! It happens on this date! --must be simply _irresistible_. I mean: you're literally changing TIME. Hot shit! The entire population has to respond! You're changing TIME! Why give that up?

While I'm storytelling and presuming, I'll note that this needn't be a deliberate, conscious decision; I'm only suggesting that the people positioned to change this sort of thing are probably naturally wired to resist doing so, and may not even be aware of why themselves.

[kelnos]

I (living in California) usually use "PST8PDT", which does what I want, all year round (for some irrational reason I refuse to claim that I live in Los_Angeles[0]). I believe there's also "EST5EDT", "CST6CDT", and "MST7MDT" as well.

But agree that this is just a grab bag of confusing garbage.

[0] I suppose if CA does away with DST (or keeps it permanently), I will have to change...

[boulos]

Huh, your LA note prompted me to say “That’s why I use US/Pacific”. But someone on the internet tells me I’ve been doing it wrong and US/Pacific has been deprecated for years / I’m not supposed to:

https://stackoverflow.com/questions/4309030/difference-betwe...

[kenniskrag]

> toying with the idea of dropping daylight

Europeans turn back clocks for daylight saving, perhaps for last time. source: https://www.dw.com/en/europeans-turn-back-clocks-for-dayligh...

[Hamuko]

The EU DST debacle has been such a shitshow that I have trouble believing the words "perhaps for last time". And now with COVID-19, I haven't seen anyone actually focus on implementing the damn thing.

[kenniskrag]

What do you have to implement?

[datejfktn]

For once pretty much no one is aware of this supposed change. There was like a couple of articles on the day it was voted and that's it.

This will 100% not happen, it's another one of those things that the EU parliament votes that everyone ignores, and it's perfect ammunition for those complaining that it makes laws without popular consultation.

Trying to go forward with this change will generate massive anti EU backlash.

And then you have the UK problem. Having variable time offsets between EU and UK would add yet another layer of disruption on top of Brexit.

[Hamuko]

>it makes laws without popular consultation

That's not accurate.

>This online consultation, which ran from 4 July to 16 August 2018, received 4.6 million responses from all 28 Member States, the highest number of responses ever received in any Commission public consultation. According to the preliminary results (see annex), 84% of respondents are in favour of putting an end to the bi-annual clock change.

[datejfktn]

Selection effect. Those who really cared about this commented.

But what about the 99% rest of population? It's a mistake thinking that because they dont realllly care they will accept either way.

Resistance to change is huge, especially when it plays into the narrative "Bruxelles demanded it"

And what I meant by lack of popular consultation is that if you go on EU streets and ask about this change 95% of people will have no idea what you are talking about.

[andrepd]

In other words, an internet poll in which less than 1% of the population participated, 2/3 of which were from Germany.

[kjakm]

>> And then you have the UK problem. Having variable time offsets between EU and UK would add yet another layer of disruption on top of Brexit.

It's worse than just EU/UK offset. You would have Northern Ireland and the Republic of Ireland in different timezones.

[Macha]

Portugal and Spain manage it, but it would be extremely contentius among around half of the NI community.

[iso1631]

> For once pretty much no one is aware of this supposed change

The consultation had 4.6 million responses.

> Having variable time offsets between EU and UK would add yet another layer of disruption on top of Brexit.

So?

[iggldiggl]

> The consultation had 4.6 million responses.

A disproportionate amount of which were from Germany (2/3 of the responses, even though Germany only is only ~ 16 % of the EU-population pre-Brexit).

[corty]

The EU is currently one timezone for most of its area, the whole continent excluding Portugal (edit: and Finland, Greece, Baltic states) has the same timezone. But actually it should be 3 or 4 timezones if you want to be close to solar time. Also, there are people who would prefer having solar zone time +1 (so e.g. UTC+2 in Germany instead of UTC+1). The EU decided to chicken out and let the members decide for themselves. So now each country has to decide which timezone it would like to implement, and of course if a neighbour does it differently, you also got yourself a timezone boundary at your border, which people dislike. So now all the politicians are caught in a state of indecision, keeping the status quo.

[Hamuko]

>The EU is currently one timezone for most of its area, the whole continent excluding Portugal has the same timezone.

That's definitely not accurate.

[throw0101a]

A good portion of the EU is in CET when they probably shouldn't be when it comes to solar time:

* https://en.wikipedia.org/wiki/Time_in_Europe

France should probably, AFAICT, be in WET (like the UK) and Spain definitely should be. Solar time offsets are quite off for them:

* http://blog.poormansmath.net/how-much-is-time-wrong-around-t...

* https://github.com/stefano-maggiolo/solar-time-vs-standard-t...

* https://24timezones.com/world-time-zones#toc-0

[corty]

Oh, you are right, sorry. The Baltic states, Finland and Greece are UTC+2/3

[bilekas]

IE use DST also fyi.

> The EU decided to chicken out and let the members decide for themselves

There are reasons the EU doesn't just enforce timeZones across its members.. So this is a 'strange' comment that bothered me.

[corty]

I didn't mean to say the EU should enforce a timezone. The EU didn't get involved at all after the decision to get rid of DST. Not even by providing guidance or suggestions for the new timezone layout. Usually when there is something to be decided, there is a EU summit or work group. But they didn't even do that.

[marcosdumay]

Brazil spent 3 years talking to everybody, publishing the change, and making sure everybody was on the same page. Yet, all the companies providing software got it wrong at least once (some more than 3 times). The only software that got it right were community based FOSS distributions (not raspbmc... that got me).

At least all the institutions got it right, so it was enough to announce "Windows|Red Hat|iOS|Android|whatever is wrong today, ignore it and use some other clock".

[leokennis]

It will not happen. The science is overwhelming that having one timezone all year long is worse for people, and switching the clock back and forth twice a years is a minor nuisance at most.

The EU's "Ban DST" is the same populist bullshit as Trumps "inject Windex to cure COVID". Based on nothing and ignorant at best.

And the cherry on top is, if you ask the EU if they want to receive a no strings attached gift of €10.000.000.000.000 or €11.000.000.000.000, it would still take them 20 years to decide. No way they will ever reach consensus on DST.

[etripe]

If the science is overwhelming, do you have a source? If not, what are the downsides to having the same timezone all year?

[throw0101a]

[Some links that I've posted the last few times DST has come up:]

The folks who study this:

* https://en.wikipedia.org/wiki/Chronobiology

Seem to have come to a consensus that if we're going to get rid of DST, then health-wise it is best to have Standard Time year-round:

> As an international organization of scientists dedicated to studying circadian and other biological rhythms, the Society for Research on Biological Rhythms (SRBR) engaged experts in the field to write a Position Paper on the consequences of choosing to live on DST or Standard Time (ST). The authors take the position that, based on comparisons of large populations living in DST or ST or on western versus eastern edges of time zones, the advantages of permanent ST outweigh switching to DST annually or permanently.

* https://journals.sagepub.com/doi/full/10.1177/07487304198541...

For a longer-read, referencing quite a bit of academic literature, but a conclusionary snippet:

> In summary, the scientific literature strongly argues against the switching between DST and Standard Time and even more so against adopting DST permanently. The latter would exaggerate all the effects described above /beyond/ the simple extension of DST from approximately 8 months/year to 12 months/year (depending on country) since /body clocks/ are generally even later during winter than during the long photoperiods of summer (with DST) (Kantermann et al., 2007; Hadlow et al., 2014, 2018; Hashizaki et al., 2018). Perennial DST increases SJL prevalence even more, as described above.

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

Other position papers that I've dug up over the years when curiosity got the better of me:

> Society for Research on Biological Rhythms (SRBR) is dedicated to advancing rigorous, peer-reviewed science and evidence-based policies related to sleep and circadian biology.

* https://srbr.org/advocacy/daylight-saving-time-presskit/

* (refs, with pro and con): https://srbr.org/wp-content/uploads/2020/09/DST-References-S...

European Sleep Research Society:

* https://esrs.eu/wp-content/uploads/2019/03/To_the_EU_Commiss...

Canadian Society for Chronobiology:

* https://www.theglobeandmail.com/opinion/article-turn-back-th...

* https://twitter.com/ChronobioCanada/status/11906320965969264...

American Academy of Sleep Medicine (with 36 footnotes if you want to dig further):

* https://jcsm.aasm.org/doi/10.5664/jcsm.8780

* https://doi.org/10.5664/jcsm.8780

The Centre for Chronobiology, based at the Psychiatric University Hospital (University of Basel):

* http://www.chronobiology.ch/wp-content/uploads/2019/08/JBR-D...

* http://www.chronobiology.ch

(Personally, I'm just going to trust the experts on this as I don't have the energy to go digging in things. A quick cursory Google/DDG search is enough for me.)

[iso1631]

The sun rises in Singapore between 0655 and 0715 depending on the time of the year. How would changing the clock help at all?

[throw0101a]

It wouldn't, as it gets ~12 hours at both solstices:

* https://www.timeanddate.com/sun/singapore/singapore

DST is mostly for countries closer to the poles. See my other comment:

* https://news.ycombinator.com/item?id=26088383

[kenniskrag]

Never heard about windex. Now I know.

[iso1631]

> The science is overwhelming that having one timezone all year long is worse for people,

Well the majority of people, countries, and square-kilometres of land doesn't have daylight saving so you'll have to do better than that.

At some latitudes with some social norms (regarding things like school start times) DST is beneficial. In others it's not. There are no absolutes here.

[phlo]

> If you ask for output in EDT, but the date is in December (which is not part of daylight savings time) then should the date output be UTC-4 or UTC-5?

EST is always UTC-4 and EDT is always UTC-5. Both of these exist throughout the year. The only change happening in Spring/Autumn is that some places change which time zone they currently observe.

This also addresses the second problem that you outlined. As long as the query is properly specified (if you want information related to a location, use America/New York; if you want information related to a time zone, use the time zone), you can always get an unambiguous and correct answer.

[dmm]

To be pedantic EST and EDT are offsets. America/New_York is the timezone which consists of multiple offsets that depends on the time of year and date mostly determined by the local civil authority. For example in 2005, the US extended daylight saving time by four weeks. This difference between 2004 and 2006 is a part of the timezone.

[phlo]

Cool, I hadn't realized that distinction in terminology. Thanks for pointing it out! :)

[throw0101a]

> EST is always UTC-4 and EDT is always UTC-5.

Except you have those reversed. :)

[emmelaich]

< EST is always UTC-4

Unfortunately not. Australia also used EST until recently. Now they've introduced AEST, but I'm sure there's systems out there using EST.

[mikelward]

When somebody writes EST in summer they mean UTC-4. Interpreting that as UTC-5 is almost always wrong.

[kelnos]

Right, but that's because people are misinformed as to how timezones work. EST means UTC-5; people who refer to EST as current during the summer are incorrect. Most news outlets avoid the problem by just saying "ET" or "Eastern Time", which I wish more people would do.

[jmgao]

> both The USA and Canada have been toying with the idea of dropping daylight savings time

Individual states are toying with the idea as well [1], which presents a problem if one of the tzdata locations decides to change its rules. You're screwed no matter what you choose to do. :-(

1: https://www.syracuse.com/state/2020/11/state-senator-introdu...

[Izkata]

It gets worse: DST in Indiana has to be handled on a per-county basis for anything prior to 2006.

https://en.m.wikipedia.org/wiki/Time_in_Indiana

[spiralx]

It gets worse: from when I had to deal with this some years back IIRC in Saudi Arabia the start and end of DST is set by decree every year.

[siculars]

They already do. See Arizona.

[1-more]

…and then see Navajo reservation in there, and then see the Hopi reservation inside of that!

[kenneth]

I just always write ET, PT, MT, CT.