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.
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...
> 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.
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.
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.
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...
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 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.
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 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.
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.
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 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.
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 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...
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.
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.
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.
[+] [-] imglorp|5 years ago|reply
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
[+] [-] SahAssar|5 years ago|reply
[+] [-] grishka|5 years ago|reply
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.
[+] [-] jcranmer|5 years ago|reply
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.
[+] [-] mschuster91|5 years ago|reply
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...
[+] [-] reader_1000|5 years ago|reply
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.
[+] [-] Jabbles|5 years ago|reply
[+] [-] jt2190|5 years ago|reply
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.
[+] [-] app4soft|5 years ago|reply
To be clear, the software perspective is to use Unix time instead.[0]
[0] https://en.wikipedia.org/wiki/Unix_time
[+] [-] tgv|5 years ago|reply
[+] [-] ehvatum|5 years ago|reply
[+] [-] throw0101a|5 years ago|reply
* 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...
[+] [-] dahart|5 years ago|reply
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.
[+] [-] ascar|5 years ago|reply
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.
[+] [-] ghaff|5 years ago|reply
[+] [-] runarberg|5 years ago|reply
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.
[+] [-] globular-toast|5 years ago|reply
[+] [-] Pandavonium|5 years ago|reply
[+] [-] geerlingguy|5 years ago|reply
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.
[+] [-] acdha|5 years ago|reply
[+] [-] jibbit|5 years ago|reply
[+] [-] vaccinator|5 years ago|reply
[+] [-] reidacdc|5 years ago|reply
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.
[+] [-] mrfusion|5 years ago|reply
[+] [-] throw0101a|5 years ago|reply
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...
[+] [-] tzs|5 years ago|reply
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.
[+] [-] mannykannot|5 years ago|reply
[+] [-] tom_|5 years ago|reply
[+] [-] Aaargh20318|5 years ago|reply
[+] [-] Hnrobert42|5 years ago|reply
[+] [-] input_sh|5 years ago|reply
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.
[+] [-] _ph_|5 years ago|reply
[+] [-] lotsofpulp|5 years ago|reply
[+] [-] swebs|5 years ago|reply
>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.
[+] [-] novia|5 years ago|reply
[+] [-] chapium|5 years ago|reply
[+] [-] cbanek|5 years ago|reply
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.
[+] [-] User23|5 years ago|reply
[1] https://www.mercurynews.com/2016/10/30/the-year-daylight-sav...
[+] [-] varispeed|5 years ago|reply
[+] [-] macg333|5 years ago|reply
[+] [-] throwaways885|5 years ago|reply
[+] [-] rvr_|5 years ago|reply
[+] [-] shirro|5 years ago|reply
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.
[+] [-] notsuoh|5 years ago|reply
[+] [-] Adutude|5 years ago|reply
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.
[+] [-] andyv|5 years ago|reply
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.
[+] [-] rapjr9|5 years ago|reply
[+] [-] kingkawn|5 years ago|reply
[+] [-] new_realist|5 years ago|reply
[+] [-] ReptileMan|5 years ago|reply
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.