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Governments Worldwide Consider Ditching Daylight Saving Time (scientificamerican.com)
432 points by pseudolus on Oct 31, 2020 | hide | past | favorite | 270 comments



Social issues aside, the software perspective of keeping up with DST is very costly.

Every time any government entity anywhere on Earth changes its mind about what zone they're in and when, the IANA needs to reissue the TZDB. Then every OS and platform vendor needs to patch up to a new TZDB. Just for laughs, Java seems to have its own TZDB so in general your OS and application layer might disagree about zones.

This is all okay for most users who just get an automated OS push, but some vendors operating national networks that need to do some things in localtime need to upgrade their platforms and do acceptance testing every time.

And then there's bugs.

Just for example about the variations, here's a recent TZDB change, seems Fiji is rejiggering their dates only a month away. See the archives for many more.

https://mm.icann.org/pipermail/tz-announce/2020-October/0000...

https://www.iana.org/time-zones


The West Bank has (had?) timezones that are based on ethnicity, not geographic location: https://www.972mag.com/the-worlds-only-ethnic-time-zone/


Every time I consider this I'm reminded of an incident where 3 Israeli Arabs blew themselves up instead of their target, probably due to daylight savings time.

https://www.independent.co.uk/news/world/clocks-change-kille...


That’s straight out of Tintin and the Broken Ear, where a would-be terrorist blows himself up after a time change: https://imgur.com/gallery/27jxctY


I have a collection of 'mistakes you make exactly once,' mistakes that are so obvious in retrospect and terrible in consequence that you would never, ever do it again.

This is a whole other class, though.


Care to share? I am sure that would be very useful for me (and probably many others).


This reliance on OS updates is a really big problem for devices that rarely receive any, like Android phones. As an Android developer in Russia who worked on a very popular app when our government changed timezones, and then did it once again a year later, I wasn't thrilled. People started doing the silliest thing: instead of picking a timezone with the correct offset, they just set the time to read correctly, thus shifting the unixtime by an hour. They then proceeded to complain that my app doesn't show relative dates correctly (I just posted it but it says hour ago). Had to add an ugly workaround involving getting the known-correct current unixtime from the server and using the offset from that in all my time calculations. Fun times.

And no, you can't update the timezone database yourself. It resides on the system partition which requires root or at least an unlocked bootloader to mount as writable.


> seems Fiji is rejiggering their dates only a month away

If I recall, Egypt's DST change several years ago was announced so close to the changeover that IANA was updated after it happened. It's possible there is even an instance where the DST change was enacted retroactively.


> Just for laughs, Java seems to have its own TZDB so in general your OS and application layer might disagree about zones.

Java also ships their own SSL trust store instead of using the system one. Why, just why?! Every system capable of running Java also has its own trust store...


Yeah, I find this really annoying too. Java has all the right integration to windows trust store and you can write custom code to use it. But it’s not sued be default.

This makes using internal CAs a nightmare.


> Every system capable of running Java also has its own trust store

No, they don't: https://en.wikipedia.org/wiki/Java_Card

there are also other examples of java running in embedded and semi-embedded scenarios where a TZDB and a SSL trust store would not be guaranteed by the host.


Even if that is true now, it certainly wasn't always true. When did Java add its trust store, and when did Windows and Debian and Solaris?

There's also a consistency issue --- write once, run everywhere doesn't work if you need to resign your webstart program based on the OS you're running on.


Not sure about that, the Windows certificate store has been around since forever, perhaps even since Windows NT. The same goes for certificate management in Linux. I think it was mostly because it was far easier for the Java team to roll their own extendable store instead of doing all the platform integration themselves.


> Just for laughs, Java seems to have its own TZDB

Well, there is also Joda time and icu4j that have their own TZDB which caused me one very stressful day until we found this fact.


To the original point, then there’s people like me that spend time actively ripping out “vendored” copies of tzdb in OSS libs to make them instead use “the one true copy” that is itself painstakingly kept accurate everywhere. Then add the extra time required to update those patches when new versions are released... Copying/vendoring dependencies like that is a great shortcut for a project but creates a huge hassle in large systems (a single OS counts, thousands of packages).


That won't go away, software will still be needed for when states inevitably change their timezones.


I expect that to happen far less often.


Right. OP's is more an argument against time zones than Daylight Saving Time.

Honestly though, this should only be a problem for the small subset of embedded software without access to the Internet. If major OSes time zone databases are not able to be updated independently of the rest of the OS, that's kind of on them. We know time zone boundaries have been changing arbitrarily for decades, so shouldn't this be a solved problem?


Not against zones; I was hoping to shine a light on all the complexity around the TZDB, which is a mapping of zones to switchover times. Eg,

    $ zdump -v US/Eastern | grep 2020
    US/Eastern  Sun Mar  8 06:59:59 2020 UT = Sun Mar  8 01:59:59 2020 EST isdst=0 gmtoff=-18000
    US/Eastern  Sun Mar  8 07:00:00 2020 UT = Sun Mar  8 03:00:00 2020 EDT isdst=1 gmtoff=-14400
    US/Eastern  Sun Nov  1 05:59:59 2020 UT = Sun Nov  1 01:59:59 2020 EDT isdst=1 gmtoff=-14400
    US/Eastern  Sun Nov  1 06:00:00 2020 UT = Sun Nov  1 01:00:00 2020 EST isdst=0 gmtoff=-18000
If everyone simply picked a zone and stayed there, without the switching schedule above, you'd only need a mapping of zone to GMT offset and be done with it.


Ahh you’re right. Missed that!


> Java seems to have its own TZDB so in general your OS and application layer might disagree about zones.

More precisely, the Java Virtual Machine (not the programming language) will, like any operating system running inside a VM, need to be patched with the new time information. Updating the host machine’s time info is not enough.


Why does JVM need to know about time zones?


It's not the VM engine (JIT compiler, etc.) itself, of course. It's a data file that resides in the Java Runtime Environment directory, and some of the standard library code uses this file.

I assume it's done this way because it's the most foolproof way to get consistency across all platforms.

If Java did delegate, it might be hard (or even impossible?) to get the same behavior out of all the different underlying APIs on each platform. And it would be challenging to create the tests to validate that it really does behave consistently.

Also, although it creates extra maintenance work, it has the advantage that it decouples Java-level and OS-level updates. Suppose development machines run one OS (with its TZ data) but QA and production run a different OS. To harmonize environments as closely as possible, it's helpful that you can keep the TZ data versions on all JVMs in sync without relying on multiple OS vendors' patch processes to enable that.


I guess it allows you to implement a JVM that runs on bare metal, or a host without timezone support.


Yep, it makes it easier to port the JRE to platforms like Windows that have an entirely different TZ system. Python, for example, has the same problem. Historically, Python took the stance of providing a "naive" datetime module that provides a conversion API, but delegated the actual TZ conversion to external implementations (dateutil, pytz). Only recently (as of 3.9) have they added a stdlib implementation that uses system-level zoneinfo by default.


Java is not an operating system. Other environments, such as .NET Core, don’t have any issues using the OS timezone database: https://devblogs.microsoft.com/dotnet/cross-platform-time-zo...


> the software perspective of keeping up with DST is very costly.

To be clear, the software perspective is to use Unix time instead.[0]

[0] https://en.wikipedia.org/wiki/Unix_time


Not really.

Most machines use UTC internally (with varying epoch dates to represent it). And this is absolutely great until you need to interface with meatbags, ie local time. It's not just display of time either: think about anything Cron does in localtime, eg backups or open building door locks, or send an ACH payment file; then ponder all the corner cases of DST switches. Eg do you do something twice, or never? What if you reboot somewhere in the DST switch period? etc. All these shenanigans are dictated by the TZDB.

Oh, and UTC also contains leap seconds.


I doubt anyone wants something to occur twice, but they might have an opinion on whether a 1:30am job should occur on the first 1:30am or the second 1:30am in the fall change. For the spring change, I think all jobs scheduled between 2am and 3am (a period that collapses into a moment) should ideally occur at said moment, but I can see how a smear might be more practical in many cases.

I don't recall how `cron` and other schedulers handle it, though.


Every software service I’ve worked on has had issues around DST transitions. That’s really the only programming benefit I see for getting rid of it going forward.


I worked at a big tech company for half a decade, and without fail, every year there was some kind of serious bug caused by DST.

Things either happened twice or never, it was always really painful. In any growth company, I would imagine that these things keep occurring, as people haven't hit the bugs themselves yet.


> Most machines use UTC internally

No, they rally aren't. Most machines use Posix time internally, and the fact that it doesn't reflect real-world leap seconds is a problem.


Unix time says nothing about which timezone you're in.


I think that's the point


Very costly? That would require some serious evidence. And even then, so what?


> And even then, so what?

I have to agree. The function of software is to reflect the state of reality as it is. Human sociopolitical reality is complicated; that's just a problem to deal with.


Software developer: The world should adjust in order to make my life as easy as possible.

The world: LOL


Agree, but it's our job as nerds to tell society about this cost.

Society's job is to weigh this cost with all the others +/- and decide what to do.


The George W Bush time change was the epitome of this, for me. Oh yeah, I’m updating TZ files because W CARES ABOUT GLOBAL WARMING!!!


It should be noted that 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...


Yeah, so I’ve followed the citations from SRBR’s position paper in the past https://news.ycombinator.com/item?id=24314134

And I found that the research was being quite seriously misrepresented. Based on reading the paper and reading quite a few of the papers they cite, I do not believe there is evidence to justify a claim that there exists any measurable health differences between staying on daylight vs staying on standard. This appears to me to be someone’s agenda, and not something the research we have actually supports.


> This appears to me to be someone’s agenda, and not something the research we have actually supports.

Other position papers that I've dug up 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 co): 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 that you seem to have to go digging in this fashion. A quick cursory Google/DDG search is enough for me. Please don't take this post as an attack or anything.)


Hi, thank you for the reply.

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

Are you saying you're dumping a pile of research links into this thread that you haven't even bothered to read, just because it showed up on Google?

I do appreciate the diplomatic tone and pile of links (you seem to have plenty of energy!) but your appeal to authority is ducking the two actual questions I've asked: why do you care - what stake do you have in this debate - what is prompting you to keep posting links to SRBR, especially if this is only the result of a quick cursory Google search? And secondly, why are you convinced by SRBR's position claims after I've pointed out several (easily verifiable) citations that fail to support the claims they're being used to make?

Maybe I'm wrong, and there is scientific consensus. I don't know because I haven't studied long enough. All I know is that SRBR's publications tickle my spidey sense BS meter a little bit. Now that I've verified myself they're playing fast and loose with some of their scientific research, it's going to be difficult for me to trust anything they say.

It would take less time than you've already spent promoting SRBR links in this thread alone to go verify a few of the sketchy citations I called out explicitly. Have you tried to verify the problems I called out?

Why blindly trust experts that mislead?


We live in the post-Gutenberg world and I don't have time to research every topic in every specialization. I do not have time to read the IPCC's entire climate change report, so will maybe look at the Abstract or Conclusion. See also experts on COVID-19, vaccinations, and GMO foods.

A lot of the discussion on DST seems to be "well I like later sunsets". Great. I like not having to wear a mask everywhere but do so anyway because that's what the expert consensus is.

The various Chronobiologist and Sleep Experts are putting forward (consensus?) statements that Standard Time is best, so I'll follow that. If you want to dig into the various Societies' position papers on DST/ST have at it. HN has all sorts of disagreements on all sorts of topic, and this may be another one of them.

I put forward these links as perhaps a starting point, and will not claim that they are an end point. If you want to argue against PhDs and say it's Snake Oil, I'm not going to contend it as I haven't put in the work (perhaps like you have).

I have been curious about DST (and time) for a while, especially since the IT drama of the DST time change during the Bush years, but the specific subject of DST popped up again last year due to the op-ed by the Canadian Society for Chronobiology:

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

If you think it's Snake Oil feel free to talk with the authors who work at various Canadian universities:

* https://www.mcgill.ca/microimm/nicolas-cermakian

* https://biology.gradstudies.yorku.ca/faculty/p-thomas/

* https://ovc.uoguelph.ca/biomedical-sciences/people/faculty/T...


Hey I'm still curious about it too. Thank you again for your reply and explanation!

I don't think the field of chronobiology is snake oil. My only problem is some of SRBR's citations seem to be used to make stronger claims, stated with far greater certainty than the research actually supports. So the question, naturally, is why? You do care if the links you're posting, even as starting points, are fully true, partly true, or not true? Have you checked any of the citations I called out? (It would take no more than a few minutes.) Do you agree or disagree with my take?

> A lot of the discussion on DST seems to be "well I like later sunsets". Great. I like not having to wear a mask everywhere but do so anyway because that's what the expert consensus is.

Let's not get too carried away with analogies, there's a pretty big difference in the study, certainty, magnitude and consensus of disease prevention strategies right now than there is in the barely directly studied and marginal tradeoffs of DST. More or less all of the research you've posted talks about lack of direct study of DST time shifts and the need for more research (which is why the "strong" claims and conclusions seem especially problematic).

A lot of the research you're posting seems to boil down to "well we should wake up with the sunrise, not before", which could well be true. Abolishing DST in favor of standard time is being advocated for the reason that staying on DST pushes winter waking to before the sun comes up. I don't want that, it's a little difficult and depressing and puts the morning winter commute into darkness.

If standard time is that much more important than DST, what is happening to people in Finland, Norway, Iceland and Svalbard, where the time shift becomes irrelevant compared to the sun shift? Are they unhappy, unhealthy or dying?

Getting rid of DST means we're out of sync with the sun in the summer. If you believe it's important to rise with the sun in the winter, then it's probably not fair to characterize DST as "I like later sunsets". Is it also bad to sleep well past sunrise, and then go to bed well into darkness, or would it be better to let the sleep schedule slide to be more aligned with sunrise and sunset in the summer? It seems like all the biological reasons to advocate for winter alignment shouldn't be selectively ignored during the summer, right?

This is why I asked in another subthread whether neither daylight not standard is ideal, and we should rise with the sun. That's what animals do naturally, and what humans likely did before industrialization, right?


For me your snippet was just a bit too short to get a feeling on the context of the conclusion. The other two paragraphs of the summary make it much clearer.

Here they are:

A solution to the problem is shown in Figure 2C, which contains a combination of obliterating DST (in favor of permanent Standard Time) and reassigning countries and regions to their actual sun-clock based time zones. Under such adjustment, social (local) clock time will match sun clock time and therefore body clock time most closely. Critics of such a solution might argue that this would scatter European social times, but there is no evidence that this would be detrimental. First, we already have three different time zones within Europe (WET/GMT, CET, and EET), and secondly, the United States has four different time zones and several United States states even have multiple time zones with no detriment in commerce, travel, or communications.

If DST should be abandoned, as we suggest as scientists, there are still many people who “like their long evenings.” But there is a solution to this problem: DST is simply a work-time arrangement, nothing more than a decision to go to school/work an hour earlier. As such, it is not a decision that should be made by the world, by unions of countries (e.g., the EU), or by individual countries, neither at the federal nor the state level. Work-time arrangements are decisions that a workforce could decide at the company level. Therefore, anyone who wants to spend more time at home in daylight after work should convince his/her company and co-workers to advance their start time during certain months of the year or even better: introduce flexibility for individual workers where possible to accommodate differences in personal biological and social requirements.


However, I think it’s actually easier to change the clock than to change the norms. (Which is silly!)


Surely it depends on latitude and where you live in a timezone (as well as individual preferences). If Boston were to stay in Eastern time (and it probably would because New England switching to a different timezone than the rest of the east coast and an hour further from the west coast has its own problems), the elimination of DST would move sunrise back to about 4am in midsummer.


Longitude, but yes.


No. I actually did mean latitude because that affects the length of the day at different times of the year. On the equator, there's not much point. Presumably, you're in a timezone that makes general sense relative to typical work patterns so that the sun is up during your awake time. Conversely, live in northern Alaska and you probably have almost too much sun in the summer so no need to optimize and it's dark enough in the winter that no fiddling with timezones is going to give you enough light.


To echo in as a person in Washington, I would definitely prefer my summer mornings to start later and my winter evenings to end later.

It has been getting dark at 5, tomorrow it will be dark by 4.


MN here. I would be much happier with Daylight time year round as well.


This is only anecdotal, but I grew up in a permanent daylight savings time north of 60°. I remember being a teenager and having a really hard time waking up 3 or 4 hours before sunrise.

In the past few years health experts from this country have advised a move from the permanent daylight savings to standard time, citing health benefits of good night sleep, particularly for teenagers. The polling shows quite some support for it (over 50% if I remember correctly). However the government decided against the move for arbitrary reasons despite all this.


Is this based on the fact that the vast majority of people start work at arbitrary wall clock times, usually on the hour some time between 06:00 and 09:00, depending on profession? I'm all for keeping standard time just it makes slightly more sense for 12:00 to be the time when the Sun is highest in the sky, but surely any choice is completely arbitrary and the only thing that matters is the phase difference between circadian rhythm and solar rhythm.


You can't have 12:00 be the time when the sun is highest unless you're willing to shift to infinite time zones.


But you can set up timezones, so that the difference is minimal when rounded to full hours. The high point of the sun doesn't need to be precisely at 12:00, that would be silly, especially as the high point of the sun has a seasonal variation too. But we can keep the difference small.


You can have it be closer to 12 than to 1 with only 24 timezones though.


Well, I want it closer to 1 than to 12. It’d be weird for 1 PM to be less directly overhead of a sun than 11:30 AM.

// Pure opinion, formed living in southern U.S., northern Europe, and equatorial Africa. But ... I could get over it.


As someone who grew up in a permanent DST (true noon closer to 13:30 on average) north of 60° I can tell you that you probably wouldn’t want to be a teenager forced to wake up 3-4 hours before sunrise in large part of the winter. Health experts from said country don’t want that either for the general population and have advised the government to move to a permanent standard time instead, an advice which the government has since chosen to ignore.


As a professional adult that works 10-6, working past sundown for a shorter amount of time is preferable.


So you want "midnight" to refer to "approximately one hour from the middle of the night".


Closer to 12:30 or slightly later on average, I think. But since it's a range at least an hour wide it's more like: the middle of the day/night will be as close to 12:00 as possible, but no earlier, anywhere the timezone reasonably fits.


I think this perspective misses the evening effects. There might be cultural reasons for people to stay up later (e.g. something on television, or an ongoing online group chat). There might also be the case that some people have a hard time going to sleep earlier then x hours after sunset.


DST tracks sunrise, not noon. Noon happens at the same time throughout the year.


Having young kids, I'd love to see the changing of the clocks go the way of the dinosaurs. I don't care which way, just pick one and stick with it.


Same. Pets and other animals also don't care about the time on the clock. It's not like they notice it's DST or not and shift waking up by an hour.

Besides the software insanity it causes there's a real human cost, and it wears me down for at least 2 weeks until everyone starts adjusting.


I non-ironically refer to it as “we hate parents” day. Since the benefits are imaginary it seems like an easy win relative to the costs.


Do children not need more sleep in winter, like adults?


Perhaps in places that have winter.

Florida's 4 seasons are summer (13 months), not summer (13 min), wildfire and hurricane. Hurricane is usually the best of the lot.


When my kid was 1 year old, she was on a sleeping schedule where I would wake her up just in time for me to get her to daycare before heading to my 9am daily standup, and then falling asleep at night at whatever time she would be sleepy as a result of the morning wakeup time.

Maybe I could have planned for the clock change better and done something gradual but, the abrupt way we did it had the effect that she was totally thrown off and could only sleep a couple of hours on each of the two nights following the change.

As luck would have it, staying up with her all hours for those two nights that year left me with a terrible cold that left me miserable and exhausted for more than a week.

I don't know if this answers your implied question or not. But that's what happens to many parents every year.


Yes, and precisely on November 1st this year my child will start sleeping exactly one hour longer in the morning, because it is now official of course. Huge /s, obviously.

Whether or not children need more sleep in the winter, they'll by and large be waking up at about the same unshifted time tomorrow as they did today.


why not go halfway? AKA DST - 0:30


It isn’t a negotiation over how much to change. It is a debate as to whether it should change at all. And no one seems to be arguing that it should still change. This is just lack of political will to push the legislation.


Perhaps no one likes changing. But I bet, especially in mid-northern latitudes, that a lot of people really don't like having to choose between:

- sending kids to school, driving, and doing outdoor work in winter pitch black and

- having the sun streaming through windows at 4am in the summer at the cost of an hour of long summer evening

even less appealing.


You do know that institutions such as schools can change the time they start, right?


It actually can be quite difficult as school start time isn't independent of many other schedules, including school buses picking up other grades starting later. So, no, they can't necessarily. Kids going to school in the dark was one of the major reasons cited for not renewing the all-year DST experiment. I suppose you could find a way to change or just give them flashlights but, in any case, it was a public issue in the past.


Typically this is something that would be changed on the scale of the school system of a county. That resolves the school bus issue. As far as kids being picked up in the dark.. again, the school system can change start times during certain parts of the year so that doesn't happen.


When the argument is specifically about disruption, you could solve that by shifting the clock in 10 or 15 minute increments, weeks apart.


in that case, lets just go to universal time and let businesses tell you what time to come in


I'm in favor of a full global switch to TAI. UTC is another good option, but I don't really see the benefit of keeping up with leap seconds considering the complexity they add.

https://en.wikipedia.org/wiki/International_Atomic_Time


The article is mostly suitably modest about mechanisms, focusing on the epidemiology of the observed effects, and it's more or less obvious to me that the transitions are disruptive to everyone, and especially so to sensitive individuals.

But there's also a bit in the answer to the fourth question (about long-term vs short-term impacts) that mentions effects of "chronic circadian misalignment". I've seen this a few times in various contexts, and it has always seemed to me that if this is what's driving some problems, one ought to be able to compare populations from different ends of an especially wide time zone, e.g. northwestern Indiana and Maine in the US, which are more than 15 degrees of longitude apart, but both in the US Eastern time zone. Surely one or the other of these groups always has at least half an hour of circadian misalignment?

Edit to add: On re-reading, I caught the bit at the end of the "abolition" question where there is a reference to what I wanted, apparently there are studies showing that people in the eastern side of the Central time zone get more sleep than people on the western side. There's even a link (to the Elsevier paywall, alas, but still...) https://www.sciencedirect.com/science/article/abs/pii/S01676...

Edit 2: 15 degrees of longitude, not latitude.


> Surely one or the other of these groups always has at least half an hour of circadian misalignment?

What is circadian misalignment? Nothing I see on Wikipedia backs up the idea that circadian rhythms are aligned to solar noon (which is what the interviewee in the article claimed). https://en.wikipedia.org/wiki/Circadian_rhythm

The very idea of chronic circadian misalignment due to DST seems a bit suspect since we know circadian rhythms are driven in part by changes in light, and they adapt reasonably quickly over time to changes in environment (“entrainment”). Sunrise and sunset are the main changes in light, while solar noon is one of the moments when light is changing the least. We also know computer screens and indoor lighting are affecting circadian rhythms, so isn’t it likely that games, Netflix and internet use are orders of magnitude more concerning than a one hour shift twice a year. DST is a smaller change in my sleep habits than my weekly swing!



Good to see that there is some literature, thanks!


FWIW stay curious - I was curious and followed the citations in those articles and found that there’s isn’t as much literature as is being claimed, and not a lot to directly support the conclusions. Some of the research that is cited is research into serious long term sleep deprivation, and is being assumed to apply to DST without any direct links demonstrated. For example, one of the papers cited (Koopman et al) talks about how sustained “Social jet lag” of 2 or more hours per week for years leads to higher rates of diabetes. That doesn’t directly support the idea of health risks caused by DST, nor is the difference in magnitude even discussed, but it was cited as supporting the claim that DST has serious health risks. There are at least several more examples of that in those links. Anyway, I don’t care if DST is abolished, but I’m personally more scared of agendas being cloaked in scientific sounding literature than I am of DST.


15 degrees is the the size a timezone "should" be, since 360°/24h = 15 degrees per hour.

The Western European time zone ia about 33 degrees wide, from Spain to Poland. Spain is about 2 hours off their natural time..


Spain is in the wrong timezone for seven decades, thanks to general Franco - https://www.npr.org/sections/parallels/2013/11/30/244995264/...


I’ve discovered that here on the western edge we simply arise later and work later. It’s not uncommon for people in New England to be awake at 5:30 am and starting their day.


By that logic, we could all just use UTC and set our own schedules with infinite granularity based on sunrise/sunset. I'm good with that.


That's pretty much what I do. I've worked remotely as a contractor (from the UK for mostly US companies) and I've rarely set an alarm for work in over 10 years. DST changes just slip past.


I used to care a lot about DST because I live far east in a timezone (Boston area) and had fairly fixed working hours. These days I'm remote and besides a few relatively early meetings, I'm pretty flexible so I don't really care at this point what effective timezone I'm in (within reason) over the course of a year. I might even feel at this point that the very minor annoyance of changing clocks and syncing with worldwide DST changes doesn't really have offsetting benefits for me.


I think permanent DST makes more sense. The best hours of the day are in the evening. Folks are off from work, kids are home, the heat of the day is gone. It’s a great time to get out to a park or a stroll.


> I think permanent DST makes more sense.

The chronobiologists disagree:

> 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...


The problem with the purely biological perspective is that it's too narrow. Psychology matters too.

The benefit of an extra hour of light in summer evenings is measured in happiness. You can read a book in the park, play frisbee with friends, eat outdoors with family, with all the happiness that summer light produces.

Nobody's measured it, but I have to believe that the increased happiness, reduced stress, and therefore increased health has got to far outweigh any small effects on circadian rhythms.


I agree. And don't forget about an extra hour of light in the winter! It gets dark around 4:30pm in New York during standard time, it's depressing.


What difference would it make if it got dark at 5:30 pm in the winter? That's still too close to the end of the standard 9-5 day to make much, if any, difference in what you can do before dark.


In winter it's not about activities, just about the windows not being pitch black outside while you're still at work.

Sunlight coming in windows during the day improves our mood psychologically. I mean, it's the main reason we have windows at all in office buildings. (Windows are expensive and offices already have the indoor lights on anyways.)


And you pay for that hour in the morning when kids are going to school, adults are commuting to work, construction workers are working, etc. Indeed this is basically the whole reason we switch back and forth between standard time and DST.


For you, it is one hour of light in summer evenings that brings happiness, for me, it is one hour of light in spring/autumn morning, so i do not have to wake up during night.

I would be much less opposed to DST if it were limited to 3 months around summer solstice instead of 7 months.


What do the chronobiologists say about living outside of a fixed clock schedule, and rising with the sun naturally?

I’ve ask you before, but haven’t heard an answer: why are you convinced by this research that the data is strong enough to support the conclusion? The evidence here seems scant at best to make such strong claims. (https://news.ycombinator.com/item?id=24314134) Are you part of SRBR?


It's surprising how often an article's claims turn out to be bullshit once you check the citations. Happened to me many times now.


The problem with that in more northern latitudes is permanent DST pushes the morning commute deep into darkness.

From a safety perspective, if you have to have one of the morning or evening commute in darkness, it is safer to have that one be the evening commute.

There are a couple reasons for this.

1. Mornings tend to be colder than evenings. In fact, the early mornings before sunrise are often the coldest time of the day. You are more likely to have icy roads in the morning, more likely to have snow on the roads, more likely to have fog.

If you have to drive in the dark, evening dark is usually safer.

2. Schedules are more in sync in the morning. People tend to start out of the home activities over a narrower time range than the range of times they return to the home.

In particular, school gets out early enough that most non-adults are home before it gets dark in the evening, greatly reducing the number of pedestrians and bikes that people driving in the evening dark have to contend with compared to those in the morning dark.


From November to February the commute is in darkness here in Norway (40 km south of Oslo) anyway, both ways. Staying on summer time would at least make a few more weeks have light on the way home.


Then maybe people don’t need to work at the same time in the winter, or work fewer hours. Maybe let’s take advantage of the efficiencies that technology has provided.


If we had that kind of flexibility, it would actually be a further argument against permanent DST. If people want the extra summer daylight to occur after work instead of split between before and after, go to work earlier or work fewer hours.

If we could get that kind of flexibility, it would be great. People could aim for the biologically best schedule, which would be to go to sleep at night without setting an alarm and let the rising light in the morning wake you up.


I wouldn’t care what time it is as long as it doesn’t change back and forth during the year.


I too hate the idea of losing an hour off summer evenings. Of course, the rational solution is for society to adjust its schedule, but that will never happen.


I mean if there was ever a time for it to happen, a worldwide pandemic might be it.


But you'll be gaining an hour of summer nights.

With DST, the sun goes down way too late, around 10pm in summer. With the climate as it currently is, summers have become unbearably hot and this will probably get worse in the future.

When I get home from work on a summer day, around 18:00-ish. being outside is unbearable. It doesn't get comfortable outside until the sun goes down. By moving the clock forward, you're reducing the number of hours you can actually spend outside.

Summer nights are great, summer evenings aren't. Either keep the standard time or move the clock backward during summer to maximise the number of hours you can actually spend outside, instead of the amount of sunlight.


It really depends on where you live, where I am at in the Midwest United States, as soon as I'm off from work in the summer I want to spend every waking minute outside if possible


That's really interesting. The sun goes down at the same time for me during the summer, but I love it. Where do you live perchance?

(Actually everyone in this thread should probably be prefacing their comments with their location, as it's very important for this topic).


The Netherlands. This year we again had a summer a lot of >35ºC days. You couldn't be outside without applying copious amounts of sunscreen and it was just uncomfortably hot in the sun. Nights were great though.


No, thank you. The last thing I want is the sun waking me up at 2:30am.


Society constantly shifts the schedules, so the adaption would be done in a few years.


I like DST too. (I'm at 55.4° N.) It would probably be a bit much in the winter for many, though, as daylight here would end up something like 9 am-6 pm. Very dark in the mornings, and you don't get much in the way of extra useful evening times.


The biggest win with DST is probably in the 40s of latitude or so. A lot further south and you don't have as much variation of light across the year so you might as well pick a suitable timezone and stick with it. A lot further north and there just isn't enough light in the winter to effectively use on a workday if you're indoors and there's lots of light in the summer so picking the ideal wakeup time isn't a big deal.


Indeed... where I am, over winter, it's generally daylight for, like, 8-9 hours. (Winter solstice is 7.5 hours daylight.) So pick your poison! I know what I like (which is to start work whenever, but at least leave when it was light within living memory), but it's always going to suck, at least a bit, whatever you do.


That's why we should either use standard time year-round, or even better: introduce MST (Moonlight Saving Time). where we move the clock an hour backward (instead of forward) during summer so we have more evening to enjoy.


Set your alarm one hour earlier then. No need to inflict your choice on everyone.


You don't choose your kid's school schedule, and many people don't choose their work schedule either.


> the heat of the day is gone

Or it's actually warm enough to go out and enjoy ourselves, for us folks in the northern part of Europe for like half a year.


That is mostly an illusion. Over time, the day cycle aligns with the sun, not what the clock says. People in places which are on the west side of the corresponding timezone tend to do things later than those on the east side. And since introduction of the DST, a lot of countries shifted their typical timepoints towards "later" to compensate for it.


What will it take for this to ACTUALLY happen? Every time change, I hear folks talk about how we should move to permanent DST, but nothing changes. I am tired of getting my hopes up.


EU voted to end it in 2019 (pretty decisively, 410 in favour and 192 against), and 2021 was supposed to be the final year.

Unfortunately, it was postponed once again because of the pandemic. The implementation plan is for every country to choose which timezone to stay in (summer or winter), and I guess now is not the time for nations to figure out between themselves which timezone to stay in.


The big problem is, there is no agreement about how time zones should be set up in the future. Just dropping DST would be easy and the logical thing to do. That would just need some lead time ahead to skip the spring shift.

Having each country independently decide about the time zone sounds nice, but is of course a ridiculously stupid idea in the real world. At least some minimal constraints need to be enforces as in:

- no timezone differential when you go in north-south direcion - timezone offset increases monotonic when you move east - avoid to have more than 1-hour timezone steps - and of course try to keep countries in the same timezone, which work closest together.


Here's hoping we can finally end the madness of having (temporary) UTC+2:00 in places west of Greenwich.


That would take France accepting being on a different timezone than Germany, and shifting their habits to have one hour more of darkness in the evening. I don't see it happening.


Why does it matter? It's part of the culture of those places now (eg late lunch/dinner in spain).


It’s not democracy if it can be postponed.


The fuck?

No agreement gets implemented in a day and I find it perfectly reasonable for priorities to switch in an emergency (like a global pandemic).

I despise DST as much as 80% of the EU citizens who said it should be abolished in a survey in 2018, but I'd much rather have my legislators focus on the pandemic at the moment.


> as 80% of the EU citizens who said it should be abolished in a survey in 2018

Although it should be noted that that survey wasn't exactly representative: Participants were self-selected, and participation levels varied wildly between countries. Curiously enough, around two third of the responses came from Germany, despite it accounting for only around 15 % of the EU population (pre-Brexit).


The problem is, there is a huge split amongst people, what the alternative should be. Just getting rid of DST would be rather easy. But, as you can see here in the discussion, there are other opinions. Some want to switch to permanent "summer time", even if that may a redesign of time zones, some want to introduce entirely different time concepts.


WA/CA/OR already voted to get rid of time changes, but are being held up by the federal government not giving approval. Supposedly all it takes is the blessing of some people on the executive branch.


It's already starting to happen in the EU.

>Last year the European Parliament voted to abolish the time shifts, but the member states of the European Union have yet to agree on how to implement the decision.


Hillary Clinton supported getting rid of DST. Vote people into power who prioritize making the shift.


Indiana had it, but then voted it out. Keeping time change is favored by conservatives and the campaign for it was that its so confusing to have two systems. The irony of that position was painful to witness.


Please god yes. I live in Arizona, where we have already gotten rid of it, but being sane in an insane world is still insanity. (You still have to deal with everyone else doing it.)

But as someone who spent a month fixing out a bug in Outlook about how birthdays show up one day late if they are on the time change day (it's a long story), please please fix this upstream.


This was already tried in the 70s and it sucked[1] so much so that we went back to the current method. It's strangely hard to find references though.

[1] https://www.mercurynews.com/2016/10/30/the-year-daylight-sav...


I'm surprised how much 1970s news is hard to find references to. The 1978 Tractorcade remained forgotten until just a few years ago.

There's still not much on the US domestic terror attacks (100s/yr), during the early 1970s. That one has a vibe, as if no one wants to discuss it.


You mean the Weather Underground [1], Symbionese Liberation Army, and so forth? I'm not sure how commonly "domestic terrorism" was used as a term although it was used. That was a long time ago of course but the violence associated with the Vietnam War etc. is quite well documented.

[1] https://www.fbi.gov/history/famous-cases/weather-underground...


There were over 450 US domestic terror attacks in 1970. It's relevant today because the context it provides shows how we have been historically safe from attacks on US soil for over 40 years.

The last 20 years of terror hysteria created a false mindset that Americans are at meaningful risk of dying in a terror attack. Trillions have been wasted on infrastructure - that can only be responsibly explained as a tool to nurture and reinforce that mindset.

And of course there are the ever increasing loss of civil liberties, each loss shifting power toward Gov and away from us.


Not all of it is digitized. A lot of it is still only found on microfilm in larger libraries.


This was different. They tried DST all year around. Russia also tried this in 2014 and also failed.


Assuming that people didn't like all year round DST, it's presumably because a lot of people actually like the shift depending upon where they live. DST year round means that where I live sunrise would be about 8am in midwinter. Meanwhile someone far west in a timezone is getting a relatively late dawn in the summer in spite of the fact there are lots of daylight hours.


I don't know how someone ever could think this is a good idea and also got so many governments to implement this. Whoever is behind it, he or she is a genius of evil. Let's ditch this nonsense now.


> I don’t know how someone ever could think this is a good idea

Why is that? Whether or not it’s still a good idea, lots of people have thought so in the past. You don’t see the fact that governments have implemented it as evidence that there has been consensus and something legitimate there you might have missed?

I honestly don’t care if daylight saving is abolished, but when I was younger, I used to think like you do that daylight savings was nonsense and should be ditched. But since then I’ve looked at the sunrise charts and realized what happens in the summer without daylight savings, and I changed my mind, I like what happens. Without daylight savings, summer nights are short and summer mornings the sun comes up at 4am and I sleep through some of the usable sunlight. Daylight savings is an attempt to normalize sunrise time. What, exactly, is “evil” about that?

Take a look at the annual sunrise times where you live and check out what happens with and without daylight savings https://www.timeanddate.com/sun/usa/san-francisco


Majority of time that humanity existed that wasn't a problem. Maybe this was influenced by industrialisation and 9-5 culture. It would be great if we also left behind these rigid rules when people should work (certainly the new work from home adoption could help with that). I'd rather go to sleep earlier so that the 4am feels like 5am instead of force almost entire world to change their clocks.


> Maybe this was influenced by industrialisation and 9-5 culture.

Yeah, exactly right. Before industrialization, you’d simply wake up with the sun. If you ever go camping or on long outdoor trips, you might notice your schedule becomes suddenly much more aligned with sunrise. Mine does, anyway.

> I’d rather go to sleep earlier so that the 4am feels like 5am

That’s totally reasonable, but hard to achieve alone. We agree on the workday schedule norms together as a society. Flexibility would be nice, but much of industry depends on schedules and people physically working together, so they don’t (yet) have ways to relax the rigid schedules. Another thing to consider is the summer nighttime is less than 4 hours long (not counting any twilight at all). That means if you sleep 8 hours, you do have to choose which end to cut into.


I understand that I didn't think "sleep earlier" through. I wouldn't be able to do that easily. I can't go around getting to sleep at other time than 3am, it seems like my body is fixed to that hour.


Now is that 3am standard time or DST?


I realised I should have added that. It's 3am DST, so it is a bit easier for me now that time changed.


For the majority of time humanity existed, clocks didn't. Everyone having access to highly accurate clocks synchronized to the same time and using them to coordinate activities all around the world is quite new.

I expect less rigid working styles to increase in popularity for some professions, but there will always be situations where people want to do things at the same time, which is substantially easier if they can agree about what time it is.


> What, exactly, is “evil” about that?

People literally die because of the change. Every year, extra people die so you can enjoy more sunshine in summer evenings. You dismissed these deaths because you "like what happens".


This is ridiculous.

> People literally die because vending machines fall on top of them. Every year people die so you can enjoy more chips at lunch. You dismissed these deaths because you like what happens.


I did not dismiss any deaths. What are you referring to, the morning commute? Daylight Savings time was invented before the mass morning commute via car even existed. If there are reasons to get rid of DST now for public safety, I’m for it.

But if avoiding fatal car crashes is the goal... maybe getting rid of cars is the solution, rather than obsessing over the very marginal effects of DST?

Do you drive a car?


It is natural that work is shifted towards the morning and people have time after work in the evening for personal matters. People do what is most important in the morning, because we can focus better.

Therefore worktimes need to follow the sunrise, especially beyond 45° latitudes where the sunrise shifts by more than 3 hrs between winter and summer.


But why the changing of clock settings? Could have just shown up earlier to follow the sunrise?


Work schedules are often tied to all sorts of other schedules that limit flexibility -- things like school schedules, stock market or customer hours, published hours for retail or government offices, etc. If there's a practical benefit to schedule adjustment (and there is at certain latitudes), it can often only be realized by many if society as a whole shifts.


Society managed to simultaneously shift their entire collection of clocks twice a year. Is it really that much more of a pain to instead just say "we're all simultaneously going to work and school an hour earlier for a few months"?


And then why the hell bother? You've now replaced a coordinated government-implemented system with a complete patchwork system at the company, school, and individual level.


Because for most jobs in most locales, everyone has to agree together when the workday starts. It’s not an individual choice, it’s a collective decision.


Because numbers have meanings? So that 9-to-5 stays 9-to-5 the whole year round instead of 8-to-4, 7-to-3, 6-to-2?


If numbers had any meaning it would be even harder to justify a system where 1 hour after 2am is 2am


> People do what is most important in the morning, because we can focus better.

There's a huge [citation needed] to add here. Also, needs a citation for people still being able to focus better at the morning after their clock is switched.


Well let's do that then where it makes sense, instead of a sudden arbitrary shift by an hour for all clocks, which is nowhere near enough for a 3 hour shift anyway.


I can see this as an argument for year-round DST. Now defend falling back one hour in the winter, when by your own admission a one hour shift will be insufficient to align with sunrise.


If you stay on DST through the winter, most places in the US will have a morning commute in the dark. The reason we switch is to keep the sunrise just slightly more even. The annual swing in sunrise time is just under 3 hours. With a DST switch, the swing becomes less than 2 hours, at the cost of switching twice.


It's still the same swing in sunlight time, just masked by changing the clocks. Some people will prefer sun in the morning, others in the afternoon. The answer is to allow flexibility of schedule to accommodate preferences, not switching clocks. It doesn't do anything other than mess with routines. Daylight is not saved, or extended.


> The answer is to allow flexibility of schedule

That works for a lot of us in tech with online computer jobs, but simply is not realistic yet for most of the world’s laborers.

> Daylight is not saved, or extended.

This is a framing, it depends on your point of view. Certainly I’ll agree the term “daylight savings” was conceived as a positive spin on the idea. On the other hand, if you take it as a given that work hours are 9-5, and that most people will wake ~2 hours before work to get ready, then updating the clocks relative to the work day does, in fact, give you more daylight evening time in the summer.


Yes. I can assure that most retail and service industries, to pick just two examples, are going to be keeping the same hours year round.


Every time it happens I imagine Nigel Tufnel was worldwide emperor at some point and just said, "Well, it's one later, isn't it?" And everybody just said, "Huh".

And here we are.


This was done to save electricity. More direct sun, less light and heating.

Historically in France the saving was equivalent to the whole consumption of the city of Paris over the day (maybe 10-20% of the whole country).

It seems people don't care about energy anymore ¯\_(ツ)_/¯


This was a theory not really backed by evidence. https://en.m.wikipedia.org/wiki/Daylight_saving_time

(Maybe a tiny electricity decrease and heating usage increase on average, depending on latitude - which would lead to more CO2 emissions overall, depending on the power source).

I think the idea of "change time to save power" was a fine experiment, but it clearly failed to produce meaningful results so we can stop the experiment.


It is backed by numbers. Currently in France 17% of electricity consumption goes to lightning, including 12% for public lightning. It's moving down with newer lamps using less energy and other sectors using more.

You have to think that daylight saving time was introduced almost a hundred years ago (heavily variable per region) when a significant amount of the electricity was going to (public) lightning, using lights available at the time that were very energy hungry and very inefficient.

There was a reason it was done. Seriously, it was not a failed experiment carried out by idiots, like some commenters seem to think. Usage evolved and might have made DST worthless or counterproductive, if anything removing DST might show the importance of adjusting time to match energy consumption.


“ Our main finding is that -- contrary to the policy's intent -- DST increases residential electricity demand.” [1]

When you trade lighting costs for heating costs DST may well be more expensive.

[1] https://www.nber.org/papers/w14429


Don't forget about extra A/C costs as well!


What's the problem to go an hour earlier to work during the summer? It's not like working hours are regulated by law.


1) Working hours are regulated by law. Your employment contract should state the time you work. It might not be the case in the US, especially for tech workers who can be quite flexible, but it is real in other places/jobs.

2) You don't live in a vacuum. Most people can't change their time by themselves because they depend on the rest of the world.

Maybe you take a train/bus at 7 to get to work at 8. There might not be a train at 6.

Maybe you have to drop your kids at school. The school is not taking your kid one hour back or forth as you wish.

Maybe you work in a factory/office that's opening and closing at some point, you can't work outside of these hours. You depend on coworkers who do other tasks, you may not be able to work by yourself.

That's the reality for most workers, outside of developers.


This argument never held, particularly because the brunt of the social cost is borne by regular people but we never see a decrease in our energy bills compared to prior to DST.


>>> prior to DST.

that means prior to 1916. I don't know about you but I don't have bills going that far. ^^


Look at countries where DST was implemented more recently so you can compare :P (I was in such a country when it adopted DST in the 90s and can tell you power bills were not reduced after the change).


I moved to Arizona a few year ago. DST is not practiced here and it is so nice. Even if you can bounce back from the physical toll of DST relatively quickly there is still a substantial amount of psychological anticipation regarding DST thay I, n=1, really enjoy no longer thinking about...


Daylight savings time has some really interesting effects on a macro level: https://www.businessinsider.com/daylight-saving-time-is-dead...


Here in Brazil we had DST until last year. DST here was called "Summer Time" and it was a complete cargo cult copy of what is done on the north hemisphere. The whole situation was so complicated that only half of the states on the same timezone (we have 4 TZs) had DST because of their distance from the equator line.


I know that most tech forums are overwhelmingly against DST. Not sure if there might not be a US bias as well But I enjoy the advantages. Perhaps because I live in a comparatively well organised country but I have never had an issue with technology. My phone and computer update correctly.

The benefits in summer are fantastic. I love having the time outdoors in the evening. Family gatherings. Not having to cook bbq in the dark. Sports. If we kept DST permanent year round to keep those benefits then the kids would be cycling to school in the dark in winter. It is such a small adjustment to improve quality of life. I have never understood why it is so unpopular. It might be particularly favourable at my latitude. I get why people near the equator would not want it.


I'm curious of what one would speculate would be the effect of Apple and Google and Microsoft just not observing daylight savings time. All computers and phones with operating systems just don't change times in accordance with DST.


Tech giants collude to break their software to force society to conform to their vision of how time should operate worldwide. Yeah. That will end well.


We should all just be on GMT. In software development on Pacific time, I always feel bad for the guys offshore that have to stay up late at night to make our morning meetings. It sure would make things a lot more easy from a coding perspective.

But to the point DST only adds complexity to the already complex task of converting time to GMT and back so that you can synchronize events in different time-zones, I fully support this effort.


Not following. What do you mean? Will he not need to stay up late if "all are on GMT"?


I run my entire life in UTC and no daylight savings. All of my clocks and phones read UTC.


This makes no sense. Your morning meeting will be at 17:00 UTC (for example), but it will still be “morning” in the SV office, and “afternoon”/“multiple hours past sunset”/“go away I’m asleep” for your offshore team (wherever they may be located). Changing the digits our clocks represent will only simplify those clocks, but it won’t, it can’t, it shouldn’t change business hours to 9-17 UTC everywhere. Because why would half of the world sleep when it’s light outside? Just because Europeans set UTC as a time zone and 23 as the time to go to sleep?


Guess what. You're still going to have morning meetings relative to your local solar cycle and the offshore guys are still going to joining the call at a time that they're probably thinking about bed based on their local solar time.



About twenty years ago now, the Arizona legislature put a referendum on the ballot that would have adopted switching between standard time and daylight savings time. It lost by about 80% to 20%, the most lopsided result I've ever seen.

Most desert dwellers don't want another hour of daylight in the summer, but one of the small perks of living here that there is no switch.


I got tired of changing clocks and also having to change my perception of when day/night begin (changes to timekeeping seem to have persistently made night time start earlier) so I set my home clocks to the time that seemed right to me (consistent with what I grew up with) and then use relative time timers to schedule everything else on a phone that runs on local time. A little bit of effort to start with, but it made my personal relationship with time much more coherent. Now I'm free to concentrate till an alarm goes off, and then I switch what I'm doing and my time is better managed. And I can look at my home clocks and have a very good idea of where I am in the day/night cycle that feels most natural to me. Essentially I invented my own personal time that best suites my own requirements.


I like that twice a year we acknowledge the construction of time


It’s time to go beck to solar time; optimal for health, and in the age of digital assistants, totally doable.


With so many analog clocks this is not going to be a realistic option.

That's why UTC is fine. It is based on the sun time.


> With so many analog clocks this is not going to be a realistic option.

And you'd get back the same confusion regarding public transport timetables that was the reason for creating time zones in the first place.


In the article is missing how many percentages of people are bothered. Since the benefits for the rest are quite big.

Since 8 hour jet lag requires only a night worst case two of sleep to adapt, why is this 1 hour such a big deal.


It matters in which direction you go.

Going west, you'll be sleepy very early in the evening, but then no one is really stoping you from going to bed at 7 PM and staying in it for twelve hours straight until 7AM (you probably will wake up around 2-3 AM, but there's nothing else to do at that time, so you'll probably stay in bed just out of boredom). As the result you adapt pretty quickly.

Going east is much harder: you can't fall asleep at night, and then during the day you have things to do, so you end up sleep deprived for quite long.


The other problem with west to east is that it can be hard to avoid redeyes. I do all I can to. When I was younger I used to hate "losing a day to travel." Now I'm pretty much F that, especially if it's company time. But sometimes, like flying even east coast to continental Europe it's hard to avoid.


People i know are plagued by jetlag for weeks.

Secondly the supposed benefits have never been backed by aby hard-evidence, it's all make-believe.


> Since 8 hour jet lag requires only a night worst case two of sleep to adapt

Science says it's more like 1 day for every hour of shift. I agree that when I shift 12.5 hours to go to India the worst effects are over after a few days, but I don't get back to a normal pattern until two weeks later as I return home.


This article has a very city-centric view. Rural communities, and farming very much prefer having DST. Every time removing DST has been postulated in the UK, it is the rural areas that object the most.


As a grain farmer I cannot imagine what kind of farmer is worried about the wall clock. For us, the only thing that determines if we work or not is the weather. Maybe the only advantage I have noticed is that the parts dealership is open an hour later if we have a breakdown. However, we're also not yet done for the year and won't be before we go back to standard time, so that falls apart for our late season work anyway.

Further, if the UK is anything like my country, only ~2% of the population are farmers, so even if they did all object the 98% wouldn't care and move forward anyway.


>> Only ~2% of the population are farmers, so even if they did all object the 98% wouldn't care and move forward anyway.

In Canada I think it's about 3% but they are a Very vocal political group and punch beyond their absolute numbers.


They also could also stop the entire food supply for the country if they choose to.


No we don't. Farming gets done in the dark no matter what in the winter. It's a pain to adjust to banking hour, machine shop hours, etc. Just set it and leave it.


They can decide to start waking up an hour earlier or later without forcing everyone else to change their clocks.


Also don't need to have clocks at all, which was an industrial-age invention. The concept of standardized time and hour-long timezones dates from the mid-1800s, and was a construct of the railways (which needed to publish schedules that'd be valid across long distances). Before then each village or region had its own time.

https://www.thecanadianencyclopedia.ca/en/article/invention-...


Do you think agriculture hasn't moved into a post-industrial age? Modern farms are tightly integrated into a global supply chain from imputs to product and definitely need to work on the same standardized schedule as the rest of the world.


I still don't understand how the wall clock prevents them from getting up an hour earlier or later.


Citation needed.


> When you’re in standard time, the sun at noon is, in most places, right above your head—you’re really aligned. When you’re in your daylight saving time for eight months of the year, you’re an hour off, and you're getting not enough light in the morning and too much light at night.

This seeems silly. "Noon" is a made-up thing, there is nothing in your body that "knows" it's supposed to be when the sun is right over head -- which by the way will be an hour off anyway from the eastern to the western edge of a time zone. There is nothing in your body that says you have to start "work" at 9am.

In the winter, in most of the USA, certainly the northernmost half, you are getting not enough light in the morning AND zero light 'at night' either way -- there are only so many hours of light to go around no matter where you put the clock. In the summer, at the same locations, you're getting plenty of light in both morning and night.

Having grown up in Detroit area (western edge of timezone) and then lived in Chicago (eastern edge of next timezone over), that makes as much of a difference as DST does, does it mean that people in one of those places "things are just off-kilter" regardless of DST? Which one? Or both? If this guy thinks noon with sun directly overhead is so important, he should presumably be advocating for many more timezones, perhaps with 20 minute offsets? But that still wont' actually change "how much light" we get, the sun and the earth's physical relationship that effects how much light is in a given day at a given location and date doesn't care what the clock says.

> I personally am an advocate for permanent standard. The reason I am is because I look at light as really important for our well-being, our mood and our sleep. Getting enough light, especially in the winter, is critical.

I have lived in several places in the USA, in every one I both wake up and go to sleep in darkness in winter. So I am getting all the light there is to get, either way. No DST change would change that, unless you change it so it is getting light before I wake up or after I go to sleep! Now, how much light I can get when I'm not stuck inside during work hours can change -- but it's permanent DST that would maximize the light available when both awake and not during standard business hours, which is exactly why people like it, because they want to get more light when not at work.

There's lots to say about DST, but this professor seems to have some odd theories about the "natural" state of the completely socially constructed clock time.


Not only that "noon" isn't necessarily when the sun is above your head as we have timezones, but solar noon isn't at the same point in the day throughout the year. You could be dead center in the time zone but the sun will be up to 16 minutes ahead or behind your time depending on the date.

For more - https://en.wikipedia.org/wiki/Equation_of_time


I just hope they listen to sleep sientists into which time they keep or the negative health effect this can have on society will easily be worse then the ones from switching twice a year.

(It's also not necessary intuitive which time is better and it's depending on geographical location, theoretically I guess the best would likely be keeping the change but make it gradual over many small steps instead of two large 1h steps, but that's impractical I guess).


Can we get rid of timse zone and leap seconds too?


"So you want to abolish time zones":

* https://qntm.org/abolish

* https://news.ycombinator.com/item?id=8902765 (2015)


While the article makes points that would be very good in a different era, if I want to know what time it is in Melbourne, I type "Melbourne time" into Google and it tells me. If I want to know whether it's daytime, I type "Melbourne sunrise" into Google and it tells me. Abolishing timezones is much more doable now than at any point since their invention, however the motivation to do it may also be reduced since I can also type things like "3PM Tokyo time in London" into Google


> Abolishing timezones is much more doable now than at any point since their invention,

I think you have it backwards: this is an argument for keeping timezones.

If you we get rid of timezones, and everyone lives in UTC, then you already know the time in Melbourne: it's the same as where you live. But that does not tell you the human schedule in Melbourne.

Right now, you can probably guess that business hours are "9-5" (09-17h), and so you can do a TZ lookup to see if people are in the office.

If you get rid of TZs, and the time is 22:15Z, what does that mean elsewhere in the planet? Is that business hours for LA, NY, Paris, Mumbai, Tokyo, or Auckland? Where is that when people people are sleeping?

We know what daylight hours in the local timezone are 8-8 (08-20h), so after doing a Google TZ search we know if someone is likely to be asleep or not.


Perhaps I wasn't clear enough. Abolishing timezones would be more practical now than at any point in the past, but it's also less beneficial.

It's more practical because you can almost instantly learn what hours the sun is up anywhere in the world, which lets you make an educated guess about whether people are awake or in the office (and this would work without timezones). It's less beneficial because you can almost instantly learn what time it is anywhere in the world (with timezones).


Oh no not this again... Let's invert the argument:

Before abolishing unified time

I want to call my Uncle Steve in Melbourne. What are the working hours there? Google tells me it is currently 7:00 to 15:00 there. It's probably best not to call right now.

After abolishing unified time

I want to call my Uncle Steve in Melbourne. When are the working hours there? it's 8:00 to 16:00, same as it is here, of course! Same as it is in New York, Bangalore and Hawaii, at the South Pole and on the Moon.

You get the point...


Ehh I don't think it's any more ambiguous than using a 12 hour clock which people seem perfectly capable of and the problem with available hours is already solved with calendars and other lookups.

I'd imagine days would just start at different hours, it's pretty ambiguous right now anyway for many applications such as for example the way shifts are calculated.


What benefit does getting rid of timezones get us?

Sure, it would be 9am GMT everywhere in the world, but it would still be "middle of the night" or "early morning" or "late evening" just the same. Everyone would just call that 9am GMT.

If you lived in London and wanted to talk to someone in Hong Kong, you'd still need to figure out what time makes sense for both of you. It might be 12pm GMT in London and Hong Kong, but your Hong Kong colleague is fast asleep at 12pm.


If you don't want to deal with leaps at the leaf level, they are largely absorbed by most cloud hosts and NTPDs these days. The general idea is they'll smear a leap second over a whole day or more so most applications don't see it.

People that do care about a clock second being a few microseconds +/- can still do it themselves.

https://developers.google.com/time/smear

https://docs.ntpsec.org/latest/leapsmear.html


Becareful with this. If all your ntp sources don't do the same thing, your clock can oscillate between sources.


We will inevitably, as we interact more and more with people anywhere on Earth.

I think the way to transition is to use dual time (local & UTC) in software.


You already can get rid of time zones by only using UTC.

But is is not very practical.

The time zone communicates the part of the day in any place around the world.


> You already can get rid of time zones by only using UTC.

UTC has leap seconds. You are thinking of TAI:

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


I suspect most people on the "abolish time zones" kick don't actually deal with people in other timezones very much. By knowing what timezone someone is in, I know instantly--without even consulting their calendar to find out what their usual working hours are--whether 2pm my time is a reasonable time to propose a meeting.

Similarly, every time I travel to a city in a different timezone, I'm going to have to find out what usual business hours are, when dinner typically is (which admittedly varies a bit from country to country anyway), and so forth.


That sounds great until you have to look at people's calendars anyway and have to maintain conversions between more than two time zones, some of which also jump around due to DST and other bullshit.


No, we can’t.


Those or needed though


Don't ditch it, make it permanent (year round). OK, that's purely a personal bias given that no system is going to make everybody happy. But I expect I'm not alone in preferring to have more daylight hours "after work" to allow for various outdoor activities during that time, and suchlike.


Every year in my adult life that I can remember, a week before DST start/end, endless articles on ending it.

Four decades now.

There is science and then there is political will. We have the first but none of the latter. People resist change no matter how terrible the previous situation is (like the american health insurance system).


Good! Matt Walker has a very interesting Ted talk on sleep and also mentions the negative affects that DST has on society:

https://www.ted.com/talks/matt_walker_sleep_is_your_superpow...


Note that Matt Walker has fallen from grace, at least on HN. His book "Why we sleep" used to be widely recommended around here, but there appear to be very serious scientific shortcomings affecting some of the information he presents.

See e.g. https://news.ycombinator.com/item?id=21546850

That is not to say he's wrong on every count, but take what he says with a huge grain of "might have been invented/fudged and then cited from and by himself" salt.


I wasn't aware of that, thanks for the info!


You might be interested in a counterpoint from someone who (claims to) study sleep:

https://www.reddit.com/r/slatestarcodex/comments/dwtr0m/matt...


Yes, I have seen that. The author of the article has also posted a refutation of the counterpoints, with no substantive replies by Kinkajoe.

The overarching point that guzey makes is "the book is not scientifically sound, despite Matthew Walker plainly stating in the introduction that it would be". Arguing that Walker's claims are "hyperbolic, [but] within reason", that it's ok because "it is a book intended for the public" or that all this is "justified by the important message he is trying to convey" is completely besides the point! That may all be true and not change the needle one bit on "scientifically accurate".

Making up unsubstantiated claims to ""convey a message"" in a book and then later citing the book in your own scientific papers is the exact opposite of academic integrity. Hence my advice to take Walker's work with an appropriate grain of salt.


You literally linked to the same article as the parent comment.


Wouldn't that be shocking? But in fact, the URL in question opens a specific reply to that article. How embarrassing!


Dammit, sorry.


> the negative affects that DST has on society

The last time a DST thread came up a couple of months ago, I dug into all the research being cited, and I found it being wildly overstated and sometimes outright misleading. There seems to be a group of people with an agenda to abolish DST for some reason, but I’ve become even more skeptical about these claims of measurable negative effects.

https://news.ycombinator.com/item?id=24314134

The tl;dr is that a bunch of papers are being cited that studied long term sleep deprivation, that did not study DST at all. The idea that long term serious sleep loss is bad for you is being applied to (short term, temporary) DST without any evidence that DST is causing any widespread long term lack of sleep.

I do believe strongly in sleep being healthy. But one reason I’m skeptical about supposed negative health claims of DST specifically is that a huge number of people have weekly changes in sleeping habits that are larger than the twice yearly one hour shift. What matters is getting enough sleep long term, and most people adapt to DST fast enough that it doesn’t affect long term sleep — even the article admitted that a few weeks is rare.


I am one of those people that is sensitive to the change, I always have been. I wish we just stayed on standard time year round. In the summer, the sky stays light too late and messes with my sleep. In late March and October, the sun comes up too late. I think I must be solar powered.


In the 2016 election, I would have voted for anyone who promised to stop screwing with the clocks.


I know I'm going against the grain but... I quite enjoy it. It breaks up the monotony of life. So I have to work through the occasional csv and update relative time differences? No big deal. Especially when I can just reuse last year's...


Off the top of my head, my recommendation for people who feel this way is go ahead and set your alarm clock an hour earlier during DST to simulate it. You can get the benefits of the schedule change you want without affecting people whose sleep schedules are destroyed for months due to DST. (I’m in this party and biased as a result.)


Sorry, i didnt know it messed with people so much...


More and more I'm ready to abandon time zones altogether and use UTC (or another equivalent) as my default. In the past I thought the idea to be ridiculous, but now I don't think it's so radical.


I don't think this is a good idea. People on average take a long time to develop the intuition about numbers and units. Just look how the US resists to change to metric units. Just using UTC would require everyone require a new intuition about times, and what is even worse, a different one in each location. Time zones are bad enough, but they keep the rough approximation that 12:00 is about the middle of the day. And in some regions, people just tend to be a bit "late" to compensate for their timezone weirdness.

Also, it would make any kind of writing about times basically impossible. Whenever you write a sentence like: "they met at 18:30" most people would understand that this means the early evening. But when you read: "they went for a swim at 20:00 UTC" you don't know what that means, until you know where they meet. And happen to know the timezone offset. Or have to google it. Every time you read a sentence like that.


Timezones were a Bad Idea™. Swatch tried to push Swatch Internet Time [^1] but it could never take of with the hubris of the Swatch brand and repartitioning the day into 1000 "beats". Base 2, 8, 64 or 256 would have been more useful, but 60 divides evenly into 2, 3, 4, 5, 6, 10, 12, 15, 20, 30.

Perhaps an Internet Time Zone (ITZ), Earth Time Zone (ETZ) or Digital Time Zone (DTZ) could have gotten more traction?

Please can we abolish timezones. I am totally fine describing my working hours as 03:00–11:00. We have computers now, we can update text in contracts, time-based rules and laws.

[^1]: https://en.wikipedia.org/wiki/Swatch_Internet_Time


with teams split across US and Asia, the time overlap time they get i.e. US morning and Asia evening is very important to keep things going. This becomes very challenging especially in evenings where for developers sitting in Asia either you lose 1 hour of that time or sit late and mostly it is the latter what happens. So even without a country having DST, this is severely disruptive to a very large community of people and their quality of life across the world.


"Nothing is more powerful than an idea whose time has come"

Victor Hugo


Interesting that in the last 10 years some governments that got rid of the DST were accused of dismissing global warming by their political rivals


Keep Daylight Saving Time, ditch Standard Time.


Oh please, oh please, oh please, oh please...


Right on. About time. My wife and I live in Arizona - no daylight saving time.


I hate this time switch absolutely every hour of the year - regardless of how far away the actual change is. Yes, I feel robbed of an hour for the entire duration. When it’s reset, it’s nice but not so much better - because all the wrong’s already been done. It needs to stop.


Yeah but what about half/hour or shifting timezones?


[flagged]


Aside from many excellent developers being neither boys nor men, there are also plenty of challenges to be dealt with in the field of time-keeping without DST.

See, e.g. https://gist.github.com/timvisee/fcda9bbdff88d45cc9061606b4b...


Lol, of all things


The next problem emerges when 2/6 of the countries with DST decide to observe what we call summer time, 2/6 decide to change to winter time, 1/6 decide to continue observing DST following the US model and 1/6 decide to continue observing DST following the European model.

https://xkcd.com/927/


That's called "different timezones", which we know how to deal with. (Although there is a certain attraction to everybody observing UTC.)


There was no standard to begin with - switching to happens on different dates in different countries.


Exactly. Sweden, for example, switches several weeks before the US in the fall and spring leading to a bizarre situation where the two countries are only X-1 hours apart instead of X hours. It has the strange (but sensical) effect of also moving meetings by one hour on Swedish calendars. But only meetings that were created by Americans! If the meeting was created by a Swede it moves one hour on the American calendar. This inevitably leads to some confusion. So we already have this problem, whether or not there is DST or not won’t really make it worse.


Cows will be upset.


This is so not a thing to me. I never ever realise we chabged until someone tells me and im like "oh ok".

People who complain about it are a bit "Snowflake Inc." to me.. sorry.


There's objective data that more people die after the change. What's the argument for keeping it, since it's actually more work to maintain?




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