12 ms·

Egypt cancelled DST

150 points by Mojah 10y ago

mj1586 10y ago
Details of the cancellation and the fallout effects can be found here: http://codeofmatt.com/2016/07/01/time-zone-chaos-inevitable-in-egypt/ http://codeofmatt.com/2016/07/01/time-zone-chaos-inevitable-...
_asummers 10y ago
Another African country did this a few years ago with even shorter notice (I want to say Kenya with 1 day notice, but Google is coming up empty). And Azerbaijan did it earlier this year with 10 days notice.
- michaelcampbell 10y ago
  I always get cognitive dissonance when I think of Egypt as an African country. Yet, it is.
  - Theizestooke 10y ago
    In France they usually prefer the term maghreb for the north-west african countries.
    - dr_hooo 10y ago
      That doesn't include Egypt though, does it?
      - ch4s3 10y ago
        No, from wikipedia the Maghreb is "usually defined as much or most of the region of western North Africa or Northwest Africa, west of Egypt."
        Piskvorrr 10y ago
        For hysterical raisins only: Maghreb were French colonies at the time when this name took hold, whereas Egypt was British.
  - braythwayt 10y ago
    Things are easier if you put countries like Nigeria, Congo, and Zimbabwe in the "Sub-Sahara African” bucket. Egypt is not a Sub-Sahara African country, and that makes cognitive sense.
- throwaway201606 10y ago
  Kenya lies on the equator and does not extend 800km (450 miles) north or south of it. The country has never needed and never had Daylight savings time. Day and night length are pretty much the same all year round with just a little variation. Only countries at the extreme north and south edges of Africa would need daylight savings time. Egypt, Morocco, Algeria, Libya, Tunisia and islands in the Mediterranean Sea in the north combined with Namibia, Botswana, South Africa in the South. Also need to count the two enclave nations in South Africa if we are being pedantic - so Swaziland and Lesotho join our list. These are countries where Daylight Savings Time makes sense. In practice, of these, only about 5-6 countries actually have DST - Egypt, Morocco, Namibia and Tunisia and the islands in the Med. IIRC Egypt and Libya have an on-again off-again kind of deal going on with DST.
- gerbal 10y ago
  It was Libya in 2013 http://www.timeanddate.com/news/time/libya-cancels-dst-switch-2013.html http://www.timeanddate.com/news/time/libya-cancels-dst-switc...
  - _asummers 10y ago
    That's the one, thank you.
post_break 10y ago
I wish America would shift the period from an hour to 30 minutes. I feel like everyone I know hates the change especially since it's an hour. If anything I wish we could stay on DST and not revert back.
- IgorPartola 10y ago
  Why not just get rid of DST? Is it still in any way relevant? Edit: instead of "get rid of DST" I should have said "get rid of the semi-yearly time shift". Personally I much prefer EDT over EST where I live, for example.
  - post_break 10y ago
    This is why we still use it. http://andywoodruff.com/blog/where-to-hate-daylight-saving-time-and-where-to-love-it/ http://andywoodruff.com/blog/where-to-hate-daylight-saving-t...
    - Declanomous 10y ago
      I personally think the way the United States handles time zones is a large part of the problem. I live in Chicago, some of my cousins live in South Bend, IN, and some live in Niles, MI. For a long time, Indiana didn't observe DST. Michigan was on EST and observed DST. Chicago, of course, is on CST, and observes DST. It was interesting to take trips and cross between the different systems for time-keeping. For one thing, the sun rises incredibly late on the far Western edge of a time zone, and sets quite late as well. According to this map, while Chicago and NYC experience about 10 days with sunsets after 8:30 pm, the Western edge of Michigan experiences about 130 days where the sun sets after 8:30 PM. On the flip side, Chicago and NYC experience over 100 days with sunrises before 6:00 AM, while Western Michigan does not have a single day with a sunrise before 6:00 AM. Our current system is a massive improvement over the old system with hundreds or thousands of individual time zones, at least in the sense that scheduling activities between geographically distant areas is much easier. However I think the system is much worse for the life of any given individual. I think it would make far more sense to have a single time zone for the United States, and have individuals choose their schedule based on the time of the year and their local sun. I have a lot of autonomy in my job, and I have basically been doing this for several years now. I wake up later in the winter, sometimes as late as 7:30 AM. In the summer I wake up with the sunrise and bike to work, leaving my house before 6 AM. Waking up with the sun makes getting up much easier, it reduces my energy usage, and following the schedule of the sun helped my insomnia as well. I think the idea would be really unpopular in practice, since people are used to the "9-5" mentality, where schedules are set by the clock. A lot of people live far enough South and East in their time zones not to be terribly affected by the shifting time of the sunrise. Furthermore, I can see national companies instituting policies which ignore the benefits of a shifting schedule, forcing their workers on the West Coast and the East Coast to both arrive at the same hour.
Qantourisc 10y ago
Anyone else thinks 3 days it a bit short, I know _I_ will not be specifically updating my servers to match Egypt's short notice. (Luckily I don't have any customers there, but in some cases a 3 day update window isn't even feasible.)
- dirtyaura 10y ago
  The problem is bigger for mobile OSes that typically have DST rules embedded in the OS code and updated through regular OS updated. We can expect meeting invites from Egypt to be broken for a while
  - optimuspaul 10y ago
    most mobile devices use network time and don't depend on internal dst rules
    - dirtyaura 10y ago
      You need DST rules to handle future calendar entries correctly. Current network time doesn't help you with that. Example: you have a calendar entry that is defined to happen in November 1, 2016, 10:00am Helsinki time. To show that in US Eastern time zone you need to know the DST rule of both. If the calendar entry start would be defined in UTC, you would still need DST rule of US Eastern to show it correctly.
    - drzaiusapelord 10y ago
      Yeah but the local display time will be wrong for Egyptions.
torrent-of-ions 10y ago
I wish we would cancel it here in the UK too. It's so pointless. Just stay on BST, or at least go back to GMT and leave it there. I find it really difficult to shift my sleeping pattern and it disrupts me for at least a week every time.
- samuli 10y ago
  You could try to ease into the new time by waking 5 mins earlier/later per previous morning, two weeks before the switch.
  - Pitarou 10y ago
    Or we could stop pretending that playing with timezones somehow magically gives us more hours in the day. It's like the shaggy dog story about a business consultant who was hired to improve efficiency at a port. "The first thing you need to do," he concluded, "is reschedule your tides." If it makes sense to adjust our schedule according to the season, let's just do that, instead of shifting our clocks and pretending nothing's happened.
    - JoeAltmaier 10y ago
      Hm. Have to get every employer in the land to switch at once. That's the challenge. Changing the clock does that handily.
      - banksecopsguy 10y ago
        Well, under the hoods of DST, every employer is changing their schedule (relative to the sidereal midnight) at once anyway, by agreeing to abide by DST and forwarding their clocks at once. Then why not agree to change the office timings at once?
        JoeAltmaier 10y ago
        That's what laws are for.
StavrosK 10y ago
Am I the only one who likes DST? I love the fact that it's daylight until 9 PM.
- mikeash 10y ago
  I like DST. I do not like the DST switch. If I had my way, we'd just keep DST year-round. (Really, if I had my way, we'd just use GPS time universally. But that'll never happen, while year-round DST is at least vaguely possible.)
  - febeling 10y ago
    Idea made me smile, but what about making appointments? I grant that you usually give a place, too. But to be entirely location independent, my nerd self would probably prefer UTC globally and get rid of timezones entirely :)
    - mikeash 10y ago
      GPS time is just UTC but without any leap seconds applied after 1980. It doesn't mean a position dependent time. GPS satellites transmit this, then also transmit the difference between GPS and UTC so that devices can convert it to whatever they want to display.
      - febeling 10y ago
        Now it all makes sense. I adopt your position. Thanks for disabusing me of my ignorance.
        mikeash 10y ago
        Glad to be of service. If you'd never heard of GPS time before, I can totally see how you could understand it the other way.
  - inlineint 10y ago
    In Russia there was all year DST since 2011 until 2014 (https://en.wikipedia.org/wiki/Time_in_Russia#2011_zone_boundary_changes https://en.wikipedia.org/wiki/Time_in_Russia#2011_zone_bound...) It was frustrating in December when Sun rose at 9.30am while first lecture in my university was scheduled to 9am.
evanb 10y ago
This reminds me of the excellent computerphile video https://www.youtube.com/watch?v=-5wpm-gesOY https://www.youtube.com/watch?v=-5wpm-gesOY
edwinjm 10y ago
So how will this work with Windows, MacOS, Android etcetera with preprogrammed timezone/dst tables? Are Microsoft, Apple and Google now in a rush to update the tables and push updates to all devices?
- drzaiusapelord 10y ago
  MS works strictly on a patch Tuesday schedule unless its a critical security issue. I imagine the change will be out on the 12th, although a week's notice isn't a long time. Egyptians may have to wait until next month. Android seems to be a shitshow of lack of updates, OEM/Carrier interference, etc so its always a crapshoot on when Android phones get updated. No idea about Apple. They seem to update almost randomly from my experience in the past (havent owned an OSX machine in a while, so that might have changed).
leojg 10y ago
Well at least they notify someone :P In my country(Uruguay), last year they seem to forget to notify the DST cancellation and the day of the supposed time change all devices change time and caused mass confusion.
Grue3 10y ago
After Russia cancelled DST, various websites (e.g. WolframAlpha) and software would return wrong time in Moscow for years. My phone's clock widget still gets it wrong (I had to change my location to Kaliningrad). I don't think 3 days makes much difference.
- deleted 10y ago
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- JoeAltmaier 10y ago
  When Bush changed the date, our company had millions of hand-held wireless devices that had to be updated. To avoid that debacle again, we made them contact a DST server (instead of hard-coding the dates). Because updating handhelds was a miserable process requiring retrieving them all and docking them.
- jarman 10y ago
  Russia also doubled amount of DST related problems by first making DST shift permanent, then canceling it after couple of years.
tempodox 10y ago
Good riddance. DST should be universally abolished. The original purpose of boosting productivity for a war effort has somewhat lost relevance.
deleted 10y ago
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mtmail 10y ago
More examples on http://codeofmatt.com/2016/04/23/on-the-timing-of-time-zone-changes/ http://codeofmatt.com/2016/04/23/on-the-timing-of-time-zone-... "Haiti canceled DST for at least the 2016 calendar year. It was scheduled to go into effect on March 13th, but on March 12th (just 1 day notice!) the government issued a press release canceling it."
- nathancahill 10y ago
  Guatemala tried DST for one year 2011(?) and caused mass confusion. Half the country didn't switch. Every schedule had to be double-checked which time it was in "government time" or "old time". The large religious population was especially resistant to changing times, calling the previous time "god's time" and refusing to change clocks. Guatemala canceled DST the next year. Being closer to the equator, the day length difference between the longest and shortest day is under 2 hours, so it makes no sense at all to have DST.
banksecopsguy 10y ago
I have two questions that I will ask as two separate comments. My first question: How does forwarding the clock by 1 hour in summer give one extra hour of daylight? Say, without DST on a certain summer day, the sun would normally (without DST) rise at 5 AM and set at 7 PM. Also, say that I normally work from 9 AM to 6 AM. Without DST, I am working when the sun is there. With DST in effect (clock being one hour forward), the sun would rise at 6 AM and set at 8 PM my 9 AM to 6 AM working hours still fall within the time when the sun is there. What is gained? Can you give an example of times and working hours that demonstrates the usefulness of DST in summer?
- 1_player 10y ago
  > the sun would rise at 6 AM and set at 8 PM > 9 AM to 6 PM working hours It wouldn't affect your working hours, but you'd enjoy one more hour of sunlight after work (instead of sunset at 7 PM without DST). Personally going home from work when the sun is still up makes me feel I still have a lot of time to do stuff, and conversely, I hate going to work when it's still dark, and/or coming home from work when it's dark already.
- hvjackson 10y ago
  The purpose is to put more of the daylight hours in the evening when people are able to enjoy it. And/or when it may reduce the use of electricity (though studies show it probably doesn't have much or any effect). If the sun rises at 5am, few people will be awake to take advantage of that light, so shifting it to 6am has not much effect. But shifting sunset from 7PM to 8PM gives people an extra hour of daylight in the evening.
- suvelx 10y ago
  If the sun sets at 8pm 'real', and 9pm DST, most people get an hour more daylight. Vs, the sun rising at 5am 'real', and 6am 'dst' when everybody is asleep and wants it to be dark.
- Ophiom 10y ago
  Taken straight from Wikipedia: Putting clocks forward benefits retailing, sports, and other activities that exploit sunlight after working hours, but can cause problems for outdoor entertainment and other activities tied to sunlight, such as farming. It additionally mentions that DST was most heavily implemented during the energy crisis of the 70's.
banksecopsguy 10y ago
My second question: Why do countries prefer to use DST when they could achieve the same effect by changing the work timings, school timings, etc. That is say, the work timings are 9 AM - 5 PM. Instead of applying DST in summer, they could instead change the work timings to 8 AM - 4 PM. Why is this not preferred? Isn't it simpler to keep the clock constant and the work timings variable than keeping the work timings constant and the clock variable? Personally, I think it is simpler for me to understand changes in work timings than changes in DST. Several times, I have had to perform mental gymnastics to figure out which way the clock moved and how it affects my schedule, i.e. whether I need to be sleeping an hour earlier than usual or an hour later than usual.
- protonfish 10y ago
  You are getting way ahead of yourself. The first question is "Is there any measurable value to DST at all?"
  - nilved 10y ago
    Yes. DST reduces the risk of car accidents, and the rate of robberies and violent crime. For example: http://www.businessinsider.com/robbery-rates-drop-daylight-saving-time-2015-11 http://www.businessinsider.com/robbery-rates-drop-daylight-s...
    - astrodust 10y ago
      Those statistics are total garbage. Do they compare states and provinces with DST vs. those without? No. Additionally if DST is so great, why not stay on it permanently like Russia? There's also a link to an article on "How to get six pack abs" right after, so seriously, the scientific merit of this is highly questionable.
      - trhway 10y ago
        >Additionally if DST is so great, why not stay on it permanently like Russia? http://news.nationalgeographic.com/2016/03/060309-daylight-saving-savings-time-nation-science-sunday/ http://news.nationalgeographic.com/2016/03/060309-daylight-s... “Stalin changed the clocks in the spring of 1930,” Downing explains. “He forced all of the Soviet Union onto [daylight saving time]. And then in October he forgot to tell the Soviets to fall back. So the clocks in every Russian time zone were off by an hour for 61 years.” Having mini-Stalin again, Russia started to play with time again: "Since then Russia has experimented with permanent “summer time” and now, as of 2014, eschews daylight saving time altogether for permanent Standard Time. "
devy 10y ago
Looking at the DST schedules in all the countries listed in this wikipedia article[1], it once again reminds me why timekeeping is a mess with DST observance. [1]: https://en.wikipedia.org/wiki/Daylight_saving_time_by_country https://en.wikipedia.org/wiki/Daylight_saving_time_by_countr...
willvarfar 10y ago
Oh this reawakens painful memories dealing with timezones and dates! :( The shock horror is that there isn't any standard C API nor library for dealing with time zones properly. `localtime()` will convert a time to your current timezone. You can find code that tries to work around this by acquiring locks and setting environment variables before each invocation of `localtime`. There is no API that lets you specify another timezone (except, perhaps, NetBSD which has a `localtime_rz` function). There is also no good way of getting a definitive list of work days and non-work-days for countries in the world. When working on a system fairly recently that had to avoid doing something on evenings, weekends and non-working-days in France, I ended up parsing the 'secret, can be changed at any time' tzinfo files directly and compiling my own list of holiday days in France. And then there was a horrid terrorist attack and three days of national mourning in France and my code didn't realise and that was an awful feeling.
- susam 10y ago
  I once had to spend an entire evening finding the root cause of a bug in a time parsing code I used to work on that would show up only when DST is in effect. The bug was due to the way mktime() function used the value of tm_isdst member variable of struct tm. If DST was in effect and t->tm_isdst = 0, then mktime(t) would add an hour to t and set t->tm_isdst = 1. If DST was not in effect and t->tm_isdst = 1, then mktime(t) would subtract an hour from t and set t->tm_isdst = 0. See http://stackoverflow.com/q/9041514/303363 http://stackoverflow.com/q/9041514/303363 for more details.
- viraptor 10y ago
  As I read the post, I was thinking - that won't help the situation when royalty in the UK has a baby and announces a new holiday. Well... now I have two examples why the definitive list is impossible.
  - willvarfar 10y ago
    The timezone DB is centrally maintained by the IANA, and changes happen several times a year. Most OS automatically update it over their packaging system. Its a shame it isn't extended to include national holidays and such, and that UNIX standardizes (and platforms adopt) an API for working with timezones correctly. As the IANA now manage the timezone DB, it could put the onerous on publishing and updating such a DB on each country's delegate. Even North Korea cooperates with the IANA!
bajsejohannes 10y ago
Looks like Egypt has a hard time deciding. According to Wikipedia: > [Egypt] Observed DST in 1940-1945, 1957-2010 and 2014-2015. Looking at the map on that same page it looks like Egypt, by abandoning DST, falls in line with most other countries on that latitude. https://en.wikipedia.org/wiki/Daylight_saving_time_by_country#/media/File:DST_Countries_Map.png https://en.wikipedia.org/wiki/Daylight_saving_time_by_countr...
nicolas_t 10y ago
I like DST, it's a pragmatic political solution to a sociological problem. Here's the problem. During summer, people want to enjoy more sunlight during the evening and do not care about having that much sunlight early mornings. So some countries implement DST by advancing the clock by one hour. This solves the problem but seems like a bit of a hack and is painful for developers to deal with. Now, you could say that this could be very easily solved by just having people come earlier to work during summer and having the shops having different hours during summer time and winter time. This would be cleaner, there wouldn't be the DST transition and less headaches for us poor souls who have to develop applications to deal with it. The problem with the simple clean solution is that convincing employers to change their office hours would be much harder, you'd need to fight against inertia. It'd be also very difficult to codify into laws due to the widely differing operating hours from business to business. Likewise, changing the time people eat wouldn't necessarily work because people tend to be irrational about things like time and wouldn't actually eat one hour earlier in summer which would also make it difficult to get restaurants to change their operating hours... The world is messy, people are messy and tend to resist change. So the DST is a simple hack that allows people to get what they want without an overly high cognitive surcharge and work to make that change. I work from home as a freelancer so I have a much more flexible schedule that most but I still like having DST because my friends who do not have that flexibility end up with more daylight hours in Summer.. I've lived in countries with and without DST and, honestly, I love the added daylight hours in the evening, it's enjoyable and it's a huge plus compared to countries that do not have it. I consider the very slight jetlag during the transition worth it (and honestly one hour jetlag is quite easy to handle). (Of course, if you asked me about DST last year when I was dealing with a bug that was triggered by it, I'd be ranting a lot more :-))
- paulddraper 10y ago
  "DST is a simple hack" You lost me.
  - Piskvorrr 10y ago
    Well, that's actually a very precise explanation of DST in a nutshell: like other "simple hacks", it is very simple in theory. The complexity inherent in the various details and in interacting with its surroundings (hello 2:00 AM, hello crontab) forces the hack maker and everyone else to invent more hacks, which gradually become less simple, until it's a tangled web of spaghetti hacks-upon-hacks-upon-hacks, with The Black Goat of the Woods with a Thousand Young dwelling somewhere in the middle of it all.
deleted 10y ago
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falcolas 10y ago
Time for a new zoneinfo entry (or three, looking at the comments). Plus updates to the dozens of libraries which don't use zoneinfo. Gods below dealing with time sucks. Especially historical time.
LaMarseillaise 10y ago
The entire reason for Daylight Saving Time (and time zones) existing is that many people have a cultural bias towards certain numbers appearing on the clock for certain locations of the sun in the sky. There is, however, no reason that humans should have to rise at "7am" or consider "2am" to be "late". If there were no DST, would night stop being night? Would it really make any difference that the clock reads "1am" versus "10am"? The sun and the earth do not care about our clock - the amount and availability of sunlight is not affected by what numbers we choose to use. The sun does not have to rise around "6am" (or whatever it is at your specific latitude and longitude). It does not have to be light outside at "1pm". These numbers are arbitrary and only have as much meaning as we assign to them. Supporters of DST simply assign more meaning to these arbitrary numbers than its opponents. The trouble is that its supporters have effectively (legally) forced everyone to obey their confusing cultural preferences. A more efficient solution would be to use the clock for its intended purpose: as a single standard measurement of time. Abolish Daylight Saving Time, Time Zones, and meridian identifiers. Define 00:00 as the zenith of the sun over the equator, on an equinox in a leap year, at a meridian that has no human population. By doing this, I could, for example, say "The meeting will begin at 16 on Tuesday", and everyone whom that message goes to will instantly know if the meeting is in the middle of their night, day, lunch-hour, or otherwise. No need to remember that DST is starting next week, or that my location is 7 hours ahead (maybe - you never know if my area has some other rules), or whether I mean am/pm.
- brenschluss 10y ago
  You mean, like Swatch Internet Time from the 90s? https://en.wikipedia.org/wiki/Swatch_Internet_Time https://en.wikipedia.org/wiki/Swatch_Internet_Time
- Qantourisc 10y ago
  There is 1 problem with this: roll-over of the day, during the day. This could be slightly annoying, but also fun: will you go out tomorrow ? Meaning this evening.
  - ClashTheBunny 10y ago
marssaxman 10y ago
Good. Let's all do this, please.

150 points by Mojah 10y ago

Details of the cancellation and the fallout effects can be found here: http://codeofmatt.com/2016/07/01/time-zone-chaos-inevitable-in-egypt/ http://codeofmatt.com/2016/07/01/time-zone-chaos-inevitable-...

_asummers 10y ago

Another African country did this a few years ago with even shorter notice (I want to say Kenya with 1 day notice, but Google is coming up empty). And Azerbaijan did it earlier this year with 10 days notice.

michaelcampbell 10y ago
I always get cognitive dissonance when I think of Egypt as an African country. Yet, it is.
- Theizestooke 10y ago
  In France they usually prefer the term maghreb for the north-west african countries.
  - dr_hooo 10y ago
    That doesn't include Egypt though, does it?
    - ch4s3 10y ago
      No, from wikipedia the Maghreb is "usually defined as much or most of the region of western North Africa or Northwest Africa, west of Egypt."
      - Piskvorrr 10y ago
        For hysterical raisins only: Maghreb were French colonies at the time when this name took hold, whereas Egypt was British.
- braythwayt 10y ago
  Things are easier if you put countries like Nigeria, Congo, and Zimbabwe in the "Sub-Sahara African” bucket. Egypt is not a Sub-Sahara African country, and that makes cognitive sense.
throwaway201606 10y ago
Kenya lies on the equator and does not extend 800km (450 miles) north or south of it. The country has never needed and never had Daylight savings time. Day and night length are pretty much the same all year round with just a little variation. Only countries at the extreme north and south edges of Africa would need daylight savings time. Egypt, Morocco, Algeria, Libya, Tunisia and islands in the Mediterranean Sea in the north combined with Namibia, Botswana, South Africa in the South. Also need to count the two enclave nations in South Africa if we are being pedantic - so Swaziland and Lesotho join our list. These are countries where Daylight Savings Time makes sense. In practice, of these, only about 5-6 countries actually have DST - Egypt, Morocco, Namibia and Tunisia and the islands in the Med. IIRC Egypt and Libya have an on-again off-again kind of deal going on with DST.
gerbal 10y ago
It was Libya in 2013 http://www.timeanddate.com/news/time/libya-cancels-dst-switch-2013.html http://www.timeanddate.com/news/time/libya-cancels-dst-switc...
- _asummers 10y ago
  That's the one, thank you.

post_break 10y ago

I wish America would shift the period from an hour to 30 minutes. I feel like everyone I know hates the change especially since it's an hour. If anything I wish we could stay on DST and not revert back.

IgorPartola 10y ago
Why not just get rid of DST? Is it still in any way relevant? Edit: instead of "get rid of DST" I should have said "get rid of the semi-yearly time shift". Personally I much prefer EDT over EST where I live, for example.
- post_break 10y ago
  This is why we still use it. http://andywoodruff.com/blog/where-to-hate-daylight-saving-time-and-where-to-love-it/ http://andywoodruff.com/blog/where-to-hate-daylight-saving-t...
  - Declanomous 10y ago
    I personally think the way the United States handles time zones is a large part of the problem. I live in Chicago, some of my cousins live in South Bend, IN, and some live in Niles, MI. For a long time, Indiana didn't observe DST. Michigan was on EST and observed DST. Chicago, of course, is on CST, and observes DST. It was interesting to take trips and cross between the different systems for time-keeping. For one thing, the sun rises incredibly late on the far Western edge of a time zone, and sets quite late as well. According to this map, while Chicago and NYC experience about 10 days with sunsets after 8:30 pm, the Western edge of Michigan experiences about 130 days where the sun sets after 8:30 PM. On the flip side, Chicago and NYC experience over 100 days with sunrises before 6:00 AM, while Western Michigan does not have a single day with a sunrise before 6:00 AM. Our current system is a massive improvement over the old system with hundreds or thousands of individual time zones, at least in the sense that scheduling activities between geographically distant areas is much easier. However I think the system is much worse for the life of any given individual. I think it would make far more sense to have a single time zone for the United States, and have individuals choose their schedule based on the time of the year and their local sun. I have a lot of autonomy in my job, and I have basically been doing this for several years now. I wake up later in the winter, sometimes as late as 7:30 AM. In the summer I wake up with the sunrise and bike to work, leaving my house before 6 AM. Waking up with the sun makes getting up much easier, it reduces my energy usage, and following the schedule of the sun helped my insomnia as well. I think the idea would be really unpopular in practice, since people are used to the "9-5" mentality, where schedules are set by the clock. A lot of people live far enough South and East in their time zones not to be terribly affected by the shifting time of the sunrise. Furthermore, I can see national companies instituting policies which ignore the benefits of a shifting schedule, forcing their workers on the West Coast and the East Coast to both arrive at the same hour.

Qantourisc 10y ago

Anyone else thinks 3 days it a bit short, I know _I_ will not be specifically updating my servers to match Egypt's short notice. (Luckily I don't have any customers there, but in some cases a 3 day update window isn't even feasible.)

dirtyaura 10y ago
The problem is bigger for mobile OSes that typically have DST rules embedded in the OS code and updated through regular OS updated. We can expect meeting invites from Egypt to be broken for a while
- optimuspaul 10y ago
  most mobile devices use network time and don't depend on internal dst rules
  - dirtyaura 10y ago
    You need DST rules to handle future calendar entries correctly. Current network time doesn't help you with that. Example: you have a calendar entry that is defined to happen in November 1, 2016, 10:00am Helsinki time. To show that in US Eastern time zone you need to know the DST rule of both. If the calendar entry start would be defined in UTC, you would still need DST rule of US Eastern to show it correctly.
  - drzaiusapelord 10y ago
    Yeah but the local display time will be wrong for Egyptions.

torrent-of-ions 10y ago

I wish we would cancel it here in the UK too. It's so pointless. Just stay on BST, or at least go back to GMT and leave it there. I find it really difficult to shift my sleeping pattern and it disrupts me for at least a week every time.

samuli 10y ago
You could try to ease into the new time by waking 5 mins earlier/later per previous morning, two weeks before the switch.
- Pitarou 10y ago
  Or we could stop pretending that playing with timezones somehow magically gives us more hours in the day. It's like the shaggy dog story about a business consultant who was hired to improve efficiency at a port. "The first thing you need to do," he concluded, "is reschedule your tides." If it makes sense to adjust our schedule according to the season, let's just do that, instead of shifting our clocks and pretending nothing's happened.
  - JoeAltmaier 10y ago
    Hm. Have to get every employer in the land to switch at once. That's the challenge. Changing the clock does that handily.
    - banksecopsguy 10y ago
      Well, under the hoods of DST, every employer is changing their schedule (relative to the sidereal midnight) at once anyway, by agreeing to abide by DST and forwarding their clocks at once. Then why not agree to change the office timings at once?
      - JoeAltmaier 10y ago
        That's what laws are for.

StavrosK 10y ago

Am I the only one who likes DST? I love the fact that it's daylight until 9 PM.

mikeash 10y ago
I like DST. I do not like the DST switch. If I had my way, we'd just keep DST year-round. (Really, if I had my way, we'd just use GPS time universally. But that'll never happen, while year-round DST is at least vaguely possible.)
- febeling 10y ago
  Idea made me smile, but what about making appointments? I grant that you usually give a place, too. But to be entirely location independent, my nerd self would probably prefer UTC globally and get rid of timezones entirely :)
  - mikeash 10y ago
    GPS time is just UTC but without any leap seconds applied after 1980. It doesn't mean a position dependent time. GPS satellites transmit this, then also transmit the difference between GPS and UTC so that devices can convert it to whatever they want to display.
    - febeling 10y ago
      Now it all makes sense. I adopt your position. Thanks for disabusing me of my ignorance.
      - mikeash 10y ago
        Glad to be of service. If you'd never heard of GPS time before, I can totally see how you could understand it the other way.
- inlineint 10y ago
  In Russia there was all year DST since 2011 until 2014 (https://en.wikipedia.org/wiki/Time_in_Russia#2011_zone_boundary_changes https://en.wikipedia.org/wiki/Time_in_Russia#2011_zone_bound...) It was frustrating in December when Sun rose at 9.30am while first lecture in my university was scheduled to 9am.

evanb 10y ago

This reminds me of the excellent computerphile video https://www.youtube.com/watch?v=-5wpm-gesOY https://www.youtube.com/watch?v=-5wpm-gesOY

edwinjm 10y ago

So how will this work with Windows, MacOS, Android etcetera with preprogrammed timezone/dst tables? Are Microsoft, Apple and Google now in a rush to update the tables and push updates to all devices?

drzaiusapelord 10y ago
MS works strictly on a patch Tuesday schedule unless its a critical security issue. I imagine the change will be out on the 12th, although a week's notice isn't a long time. Egyptians may have to wait until next month. Android seems to be a shitshow of lack of updates, OEM/Carrier interference, etc so its always a crapshoot on when Android phones get updated. No idea about Apple. They seem to update almost randomly from my experience in the past (havent owned an OSX machine in a while, so that might have changed).

leojg 10y ago

Well at least they notify someone :P In my country(Uruguay), last year they seem to forget to notify the DST cancellation and the day of the supposed time change all devices change time and caused mass confusion.

Grue3 10y ago

After Russia cancelled DST, various websites (e.g. WolframAlpha) and software would return wrong time in Moscow for years. My phone's clock widget still gets it wrong (I had to change my location to Kaliningrad). I don't think 3 days makes much difference.

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JoeAltmaier 10y ago
When Bush changed the date, our company had millions of hand-held wireless devices that had to be updated. To avoid that debacle again, we made them contact a DST server (instead of hard-coding the dates). Because updating handhelds was a miserable process requiring retrieving them all and docking them.
jarman 10y ago
Russia also doubled amount of DST related problems by first making DST shift permanent, then canceling it after couple of years.

tempodox 10y ago

Good riddance. DST should be universally abolished. The original purpose of boosting productivity for a war effort has somewhat lost relevance.

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mtmail 10y ago

More examples on http://codeofmatt.com/2016/04/23/on-the-timing-of-time-zone-changes/ http://codeofmatt.com/2016/04/23/on-the-timing-of-time-zone-... "Haiti canceled DST for at least the 2016 calendar year. It was scheduled to go into effect on March 13th, but on March 12th (just 1 day notice!) the government issued a press release canceling it."

nathancahill 10y ago
Guatemala tried DST for one year 2011(?) and caused mass confusion. Half the country didn't switch. Every schedule had to be double-checked which time it was in "government time" or "old time". The large religious population was especially resistant to changing times, calling the previous time "god's time" and refusing to change clocks. Guatemala canceled DST the next year. Being closer to the equator, the day length difference between the longest and shortest day is under 2 hours, so it makes no sense at all to have DST.

banksecopsguy 10y ago

I have two questions that I will ask as two separate comments. My first question: How does forwarding the clock by 1 hour in summer give one extra hour of daylight? Say, without DST on a certain summer day, the sun would normally (without DST) rise at 5 AM and set at 7 PM. Also, say that I normally work from 9 AM to 6 AM. Without DST, I am working when the sun is there. With DST in effect (clock being one hour forward), the sun would rise at 6 AM and set at 8 PM my 9 AM to 6 AM working hours still fall within the time when the sun is there. What is gained? Can you give an example of times and working hours that demonstrates the usefulness of DST in summer?

1_player 10y ago
> the sun would rise at 6 AM and set at 8 PM > 9 AM to 6 PM working hours It wouldn't affect your working hours, but you'd enjoy one more hour of sunlight after work (instead of sunset at 7 PM without DST). Personally going home from work when the sun is still up makes me feel I still have a lot of time to do stuff, and conversely, I hate going to work when it's still dark, and/or coming home from work when it's dark already.
hvjackson 10y ago
The purpose is to put more of the daylight hours in the evening when people are able to enjoy it. And/or when it may reduce the use of electricity (though studies show it probably doesn't have much or any effect). If the sun rises at 5am, few people will be awake to take advantage of that light, so shifting it to 6am has not much effect. But shifting sunset from 7PM to 8PM gives people an extra hour of daylight in the evening.
suvelx 10y ago
If the sun sets at 8pm 'real', and 9pm DST, most people get an hour more daylight. Vs, the sun rising at 5am 'real', and 6am 'dst' when everybody is asleep and wants it to be dark.
Ophiom 10y ago
Taken straight from Wikipedia: Putting clocks forward benefits retailing, sports, and other activities that exploit sunlight after working hours, but can cause problems for outdoor entertainment and other activities tied to sunlight, such as farming. It additionally mentions that DST was most heavily implemented during the energy crisis of the 70's.

banksecopsguy 10y ago

My second question: Why do countries prefer to use DST when they could achieve the same effect by changing the work timings, school timings, etc. That is say, the work timings are 9 AM - 5 PM. Instead of applying DST in summer, they could instead change the work timings to 8 AM - 4 PM. Why is this not preferred? Isn't it simpler to keep the clock constant and the work timings variable than keeping the work timings constant and the clock variable? Personally, I think it is simpler for me to understand changes in work timings than changes in DST. Several times, I have had to perform mental gymnastics to figure out which way the clock moved and how it affects my schedule, i.e. whether I need to be sleeping an hour earlier than usual or an hour later than usual.

protonfish 10y ago
You are getting way ahead of yourself. The first question is "Is there any measurable value to DST at all?"
- nilved 10y ago
  Yes. DST reduces the risk of car accidents, and the rate of robberies and violent crime. For example: http://www.businessinsider.com/robbery-rates-drop-daylight-saving-time-2015-11 http://www.businessinsider.com/robbery-rates-drop-daylight-s...
  - astrodust 10y ago
    Those statistics are total garbage. Do they compare states and provinces with DST vs. those without? No. Additionally if DST is so great, why not stay on it permanently like Russia? There's also a link to an article on "How to get six pack abs" right after, so seriously, the scientific merit of this is highly questionable.
    - trhway 10y ago
      >Additionally if DST is so great, why not stay on it permanently like Russia? http://news.nationalgeographic.com/2016/03/060309-daylight-saving-savings-time-nation-science-sunday/ http://news.nationalgeographic.com/2016/03/060309-daylight-s... “Stalin changed the clocks in the spring of 1930,” Downing explains. “He forced all of the Soviet Union onto [daylight saving time]. And then in October he forgot to tell the Soviets to fall back. So the clocks in every Russian time zone were off by an hour for 61 years.” Having mini-Stalin again, Russia started to play with time again: "Since then Russia has experimented with permanent “summer time” and now, as of 2014, eschews daylight saving time altogether for permanent Standard Time. "

devy 10y ago

Looking at the DST schedules in all the countries listed in this wikipedia article[1], it once again reminds me why timekeeping is a mess with DST observance. [1]: https://en.wikipedia.org/wiki/Daylight_saving_time_by_country https://en.wikipedia.org/wiki/Daylight_saving_time_by_countr...

willvarfar 10y ago

Oh this reawakens painful memories dealing with timezones and dates! :( The shock horror is that there isn't any standard C API nor library for dealing with time zones properly. `localtime()` will convert a time to your current timezone. You can find code that tries to work around this by acquiring locks and setting environment variables before each invocation of `localtime`. There is no API that lets you specify another timezone (except, perhaps, NetBSD which has a `localtime_rz` function). There is also no good way of getting a definitive list of work days and non-work-days for countries in the world. When working on a system fairly recently that had to avoid doing something on evenings, weekends and non-working-days in France, I ended up parsing the 'secret, can be changed at any time' tzinfo files directly and compiling my own list of holiday days in France. And then there was a horrid terrorist attack and three days of national mourning in France and my code didn't realise and that was an awful feeling.

susam 10y ago
I once had to spend an entire evening finding the root cause of a bug in a time parsing code I used to work on that would show up only when DST is in effect. The bug was due to the way mktime() function used the value of tm_isdst member variable of struct tm. If DST was in effect and t->tm_isdst = 0, then mktime(t) would add an hour to t and set t->tm_isdst = 1. If DST was not in effect and t->tm_isdst = 1, then mktime(t) would subtract an hour from t and set t->tm_isdst = 0. See http://stackoverflow.com/q/9041514/303363 http://stackoverflow.com/q/9041514/303363 for more details.
viraptor 10y ago
As I read the post, I was thinking - that won't help the situation when royalty in the UK has a baby and announces a new holiday. Well... now I have two examples why the definitive list is impossible.
- willvarfar 10y ago
  The timezone DB is centrally maintained by the IANA, and changes happen several times a year. Most OS automatically update it over their packaging system. Its a shame it isn't extended to include national holidays and such, and that UNIX standardizes (and platforms adopt) an API for working with timezones correctly. As the IANA now manage the timezone DB, it could put the onerous on publishing and updating such a DB on each country's delegate. Even North Korea cooperates with the IANA!

bajsejohannes 10y ago

Looks like Egypt has a hard time deciding. According to Wikipedia: > [Egypt] Observed DST in 1940-1945, 1957-2010 and 2014-2015. Looking at the map on that same page it looks like Egypt, by abandoning DST, falls in line with most other countries on that latitude. https://en.wikipedia.org/wiki/Daylight_saving_time_by_country#/media/File:DST_Countries_Map.png https://en.wikipedia.org/wiki/Daylight_saving_time_by_countr...

nicolas_t 10y ago

I like DST, it's a pragmatic political solution to a sociological problem. Here's the problem. During summer, people want to enjoy more sunlight during the evening and do not care about having that much sunlight early mornings. So some countries implement DST by advancing the clock by one hour. This solves the problem but seems like a bit of a hack and is painful for developers to deal with. Now, you could say that this could be very easily solved by just having people come earlier to work during summer and having the shops having different hours during summer time and winter time. This would be cleaner, there wouldn't be the DST transition and less headaches for us poor souls who have to develop applications to deal with it. The problem with the simple clean solution is that convincing employers to change their office hours would be much harder, you'd need to fight against inertia. It'd be also very difficult to codify into laws due to the widely differing operating hours from business to business. Likewise, changing the time people eat wouldn't necessarily work because people tend to be irrational about things like time and wouldn't actually eat one hour earlier in summer which would also make it difficult to get restaurants to change their operating hours... The world is messy, people are messy and tend to resist change. So the DST is a simple hack that allows people to get what they want without an overly high cognitive surcharge and work to make that change. I work from home as a freelancer so I have a much more flexible schedule that most but I still like having DST because my friends who do not have that flexibility end up with more daylight hours in Summer.. I've lived in countries with and without DST and, honestly, I love the added daylight hours in the evening, it's enjoyable and it's a huge plus compared to countries that do not have it. I consider the very slight jetlag during the transition worth it (and honestly one hour jetlag is quite easy to handle). (Of course, if you asked me about DST last year when I was dealing with a bug that was triggered by it, I'd be ranting a lot more :-))

paulddraper 10y ago
"DST is a simple hack" You lost me.
- Piskvorrr 10y ago
  Well, that's actually a very precise explanation of DST in a nutshell: like other "simple hacks", it is very simple in theory. The complexity inherent in the various details and in interacting with its surroundings (hello 2:00 AM, hello crontab) forces the hack maker and everyone else to invent more hacks, which gradually become less simple, until it's a tangled web of spaghetti hacks-upon-hacks-upon-hacks, with The Black Goat of the Woods with a Thousand Young dwelling somewhere in the middle of it all.

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falcolas 10y ago

Time for a new zoneinfo entry (or three, looking at the comments). Plus updates to the dozens of libraries which don't use zoneinfo. Gods below dealing with time sucks. Especially historical time.

LaMarseillaise 10y ago

The entire reason for Daylight Saving Time (and time zones) existing is that many people have a cultural bias towards certain numbers appearing on the clock for certain locations of the sun in the sky. There is, however, no reason that humans should have to rise at "7am" or consider "2am" to be "late". If there were no DST, would night stop being night? Would it really make any difference that the clock reads "1am" versus "10am"? The sun and the earth do not care about our clock - the amount and availability of sunlight is not affected by what numbers we choose to use. The sun does not have to rise around "6am" (or whatever it is at your specific latitude and longitude). It does not have to be light outside at "1pm". These numbers are arbitrary and only have as much meaning as we assign to them. Supporters of DST simply assign more meaning to these arbitrary numbers than its opponents. The trouble is that its supporters have effectively (legally) forced everyone to obey their confusing cultural preferences. A more efficient solution would be to use the clock for its intended purpose: as a single standard measurement of time. Abolish Daylight Saving Time, Time Zones, and meridian identifiers. Define 00:00 as the zenith of the sun over the equator, on an equinox in a leap year, at a meridian that has no human population. By doing this, I could, for example, say "The meeting will begin at 16 on Tuesday", and everyone whom that message goes to will instantly know if the meeting is in the middle of their night, day, lunch-hour, or otherwise. No need to remember that DST is starting next week, or that my location is 7 hours ahead (maybe - you never know if my area has some other rules), or whether I mean am/pm.

brenschluss 10y ago
You mean, like Swatch Internet Time from the 90s? https://en.wikipedia.org/wiki/Swatch_Internet_Time https://en.wikipedia.org/wiki/Swatch_Internet_Time
Qantourisc 10y ago
There is 1 problem with this: roll-over of the day, during the day. This could be slightly annoying, but also fun: will you go out tomorrow ? Meaning this evening.
- ClashTheBunny 10y ago

marssaxman 10y ago

Good. Let's all do this, please.