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.
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.
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.
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.
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).
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?
> 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.
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.
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.
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.
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.
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.
(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.)
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.
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.
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.
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.
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.
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.
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...
> 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!
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.
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.
> 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.
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.
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?
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.
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.
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.
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.
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.
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.
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.
>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.
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.
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.
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.
Readit News
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
https://www.independent.co.uk/news/world/clocks-change-kille...
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.
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.
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...
This makes using internal CAs a nightmare.
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.
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.
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.
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?
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.
To be clear, the software perspective is to use Unix time instead.[0]
[0] https://en.wikipedia.org/wiki/Unix_time
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.
Deleted Comment
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.
* 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...
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.
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.)
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.
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.
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.
Florida's 4 seasons are summer (13 months), not summer (13 min), wildfire and hurricane. Hurricane is usually the best of the lot.
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.
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.
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.
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!
* https://journals.sagepub.com/doi/full/10.1177/07487304198541...
* https://www.frontiersin.org/articles/10.3389/fphys.2019.0094...
The Western European time zone ia about 33 degrees wide, from Spain to Poland. Spain is about 2 hours off their natural time..
Deleted Comment
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 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’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?
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.
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.
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.
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.
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.
>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.
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.
[1] https://www.mercurynews.com/2016/10/30/the-year-daylight-sav...
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.
[1] https://www.fbi.gov/history/famous-cases/weather-underground...