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Egypt cancelled DST (icann.org)
150 points by Mojah on July 5, 2016 | hide | past | favorite | 152 comments

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.

The shift in sleeping pattern indeed is a disruption and a negative factor well studied. However it's something you're only affected by a few days or weeks at most. The positive effects are more stretched and last over 6 months. They're harder to study and I haven't seen much studies (except about the non existing energy saving effect).

I enjoy having one more hour sun in the evening in the summer. Adopting the summer time timezone in winter also doesn't make much sense, as it's already hard enough in winter to get up in the dark.

I live in Toronto, far from being the most northern city. It sometimes surprises people to learn that we're at the same latitude as Rome. Anyway, I _detest_ not just the switch from DST to Standard Time, but I also hate how we move the clock for the winter. If you wake up for work it is going to be dark, or _barely_ light out if you're lucky. But by shifting the time backwards I can't play outside when I'm done work because it is dark out. I have to bring lights with me for my bicycle. Wtf is with this? Why are we making all of the light hours during the time I'm at the office? This isn't the 1800s we don't need to milk the cows. We have the opposite problem now. We need light to play outside and we need fun exercise far more than we need a little extra light between opening our eyes in the morning and that first shower.

Actually there are fairly easily measurable benefits, e.g. to tourism due to extra light in the evenings.

Staying on BST all year would be the best thing IMO. In the winter, yes it's hard to get up in the dark, but most of the time it's dark an hour after I get up anyway too. There's not much natural light in my office so in the winter I rarely see the sun because of the idiotic timezone.

Google 'lighter later'.

Summer time is decided as the EU level: http://eur-lex.europa.eu/legal-content/EN/ALL/?uri=CELEX:320...

But as the UK is apparently leaving the EU, staying on BST will be possible...

[EDIT, typo: US -> UK]

> Summer time is decided as the EU level: http://eur-lex.europa.eu/legal-content/EN/ALL/?uri=CELEX:320....

This document only seems to specify when the switch happens for obvious coordination reasons, in the same way DST dates are decided at the federal level in the US, but states are not required to use DST (IIRC AZ does not)

I've found another document from the European Commission that seems to say that the 2001 directive actually also requires that all EU member states use summer time, not only when if they use it.


"European policy measures began to be introduced, leading to the present day situation, where Directive 2000/84/EC requires Member States to put their clocks forward one hour on the last Sunday of March and change them back on the last Sunday of October each year."

And 11.2 (page 10): "The cumulative effect of this succession of laws is that all Member States are now obliged to observe summertime, starting it on the last Sunday of March and ending it on the last Sunday of October."

Irony: that'd make GMT no longer the time in Greenwich.

That's already the case during BST.

You could try to ease into the new time by waking 5 mins earlier/later per previous morning, two weeks before the switch.

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.

It's not about more hours in the day - it's about more hours in the pub garden in the evening. I'm all in favour of that.

I would go for morning pub gardens though--might that be a solution?

Hm. Have to get every employer in the land to switch at once. That's the challenge. Changing the clock does that handily.

Not every employer has to switch at once. One company can switch, then their clients and contractors, and then /their/ clients and contractors, and so on and so forth. It's not too big of a deal if you're off by one hour vs other companies.

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?

That's what laws are for.

It's less legislative work for them to do it this way (and more work for the programmer). What you want is less work for the programmer and more work for the legislator.

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.

DST just moves the entire "coordinate" system, so all schedules adjust together. Suppose some store opens at 8 and you want to go there before school. You have time for that because school is at 9. But, oops, now school is at 8, and the store still opens at 8; the store didn't adjust its hours, whereas your school did.

You are getting way ahead of yourself. The first question is "Is there any measurable value to DST at all?"

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-s...

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.

>Additionally if DST is so great, why not stay on it permanently like Russia?


“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. "

Why does it make sense to have permanent DST instead of a permanent change in office timing? Why permanently change the meaning of what it means to be a midnight w.r.t. the sun when one can elegantly achieve the same effect by permanently changing the office hours?

Less paperwork presumably. Everyone already knows what Russian summer time is. If Russia unilaterally bumped time zones that would require a lot of administrative work.

Honestly, if the sun is such a big deal then having summer office hours would make more sense than changing time-zones.

I've had the thought floating around for years to start the day at 8AM at sunrise each day, and allow for longer/shorter day durations by just jumping the clock to 8AM the next morning at civil twilight.

I know with 100% certainty it will never happen, but I might just build my own custom clock like that for when I retire and don't care who else knows if I'm up or not. ;-)

They used to do that.

Then trains were invented, and it became a pain-in-the-ass when every damn city had 12:00 noon at a different time. And then time-zones were invented and life became sane for the east-west travelers.

Regarding trains, it was a safety issue. Standard Time (and time zones) were invented to keep train schedules sane. The reason is because two trains occupying the same section of track simultaneously causes loud noises and news articles and paperwork.

It was safety, not passenger convenience. As long as engineers kept to schedule—and railroad pocket watches were legendary for accuracy—blocks of track over the horizon could be shared by trains even going in opposite directions at different times.

Accuracy of railroad watches is a fascinating subject in itself: "a technology program that would require a level of innovative engineering that would not be seen again until the moon landings", to quote this excellent article: http://everything2.com/title/Antique+railroad+pocket+watches

In China, we do this in schools (at least in my hometown). High school starts at 8:30 in the winter, and 7:30 in the summer.

The whole reason for clocks was to know when factory workers should start work so moving the schedule was moving the clock.

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.

Oh boy.

Every time some nitwit government decides to screw with its dst (after they get done trying to set pi to 3), it's a cascading exit wound costing millions downstream.

First the OS vendor needs to scramble to get the new TZ database incorporated. This might or might not entail a lawsuit[1].

Next, the ISV's and OEM's scramble to update the OS in their offering. If you're talking life and safety equipment, validating a new OS might be expensive and painful, especially if it screws with localtime() and all those subtle bugs.

Next the field hardware has to get updated. All that embedded stuff at customer sites? Yeah. Another upgrade.

Localtime, just say no!

1. http://www.techrepublic.com/blog/australian-technology/time-...

Zulu for everyone?

Yeah, or at least sell geeks harder on UTC for most headless cases like servers and routers.

You still need localtime when interfacing with ugly bags of mostly water.

People will still want and need a concept of local time, so you'll end up with pretty much the same thing, possibly better, possibly worse, but not markedly different.

People don't need a local time, they expect one based on tradition.

If we all agreed that Zulu or Stardate or whatever was the way to go, and we had a singular planetary time, we'd all know what that time meant in local terms.

Maybe your sun rises at 00:12 and mine at 08:15. Maybe you go to work at 01:00 and we do at 10:00. Local traditions prevail.

Unfortunately establishing a world-wide time system would probably have people screaming something about the Illuminati, the New World Order or Reptilians. This is why we can't have nice things.

> People don't need a local time

People do need a local time.

> Maybe your sun rises at 00:12 and mine at 08:15.

That's already the case regardless of timezones (sunrise is currently at 02:24 in Akureyri, Iceland with sunset at 00:10)

> Maybe you go to work at 01:00 and we do at 10:00.

When shops open or close, people take dinner, the trains start and stop running or people go to work are all local time concepts. If you don't provide convenient time notations for local times people will just make their own because they need to talk about these concepts and synchronise based on them anyway. That has nothing to do with local traditions, it's a form of compression.

> This is why we can't have nice things.

UTC already exists, and foisting it on everybody regardless of their actual needs is not a nice thing, it's just technologist laziness.

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 for more details.

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.

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!

> Its a shame it isn't extended to include national holidays and such

Yes because if there's one thing I'd want to deal with it's wandering religious holidays (hello easter), religious holidays for only a subset of some local population (e.g. different holidays for muslims and hindu), regional holidays, company-specific holidays, government holidays which companies may or may not want (or have) to follow, etc… Not to mention holiday doesn't necessarily mean the people following it don't work, so what would you even do with that information?

> national holidays

These are too subjective, localized and of differing "seriousness" to be worth it. Timezones are actually objective and valuable information that should be standardized.

We have differing levels for "worth it" clearly :)

Having had to work with requirements like "send pager alerts if outside normal business hours in the UK", where UK has a standard government-controlled definition of normal business hours and a government-controlled definition of whether Easter or a "bank holiday" is a business day etc, well, my life would be greatly simplified if it wasn't required that I personally collate and maintain a diary for each country...

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.

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_countr...

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 :-))

"DST is a simple hack"

You lost me.

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.

Thanks! you described it better than I could :-)

Look around for articles on the cost of DST. Here is one estimate at nearly half a billion a year:


The problem is that it's very difficult to really quantify the long term effects of DST. I know for example, that there's an increase in heart attacks the first 3 weekdays of switching to DST so that seems bad but then the researcher noted that when reverting back to winter time, people had a decreased rate of heart attacks due to having had an extra hour of sleep. It's things like this that makes me think that it's not so clear cut.

There's also research that shows that DST reduces the amount of car accidents: https://www.researchgate.net/publication/4985756_The_Short_a...

On the contrary to a lot of studies, this study finds little proof of an increase in accidents in the first few days after the change and explains that by the fact that they considered a higher number of years (28 years) than most research.

The problem is that with DST we have the typical situation of having short term effects are relatively easy to study and will tend to be negative (due to the one less hour of sleep) but with potential long term effects that are beneficial but hard to quantify. As humans we tend to discount long term effects anyway so the discussion quickly focuses on the negatives.

    $434 million / $18.5 trillion = 0.000027
0.0027% of the GDP :)

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

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

> I love the fact that it's daylight until 9 PM.

That just doesn't make sense: it's daylight until sunset, every single day. Whatever force has led people to get up later and later in the day — and thus want sunrise & sunset to occur later in their circadian cycles — will exist regardless of whether we're on DST or not.

Mark my words, if we went to year-round DST then in a few decades folks would want to have a summertime two-hour offset; if we went to a year-round two-hour offset then in a few more decades folks would want to have a summertime three-hour offset.

Just. Quite. Fiddling. With. The. Time. Seriously. If one wants to get up earlier, get up earlier. If society wants to get up earlier, get up earlier.

This. It would be really great if we all just relaxed our devotion to time. Get up when you want. Work your hours (or don't). Eat when your appetite suggests you eat. Go out and enjoy the world in the light, twilight or dark. Sleep when you feel tired (or don't).

I dream of an employer who would understand that I want to come in later and leave earlier in the winter when I feel like sleeping when the sun goes down earlier and have less daylight in the day. Conversely, I'm happy to wake and come to work early in the summer, maybe work a few hours more than in the winter months since I've got hours and hours of daylight to play with.

> I dream of an employer who would understand that I want to come in later and leave earlier in the winter

It's called freelancing :)

It is _much_ easier to change the time than to adjust everything that's set at a time.

You're highlighting the perverseness of time management. At its best it's a giant confusing mess, and that's before we get to all the bizarre business logic that's built up over time.

I actually think it may simply be that we have signs and large printed things with times on them, and it'd be onerous to have to replace each multiple times a year (or make them bigger with a layer of conditionals based on date). Instead, we push that complexity onto the backend and deal with time there. It's certainly easier from the customer and business owner, and we've merely make life much more difficult for the programmers and engineers... which is probably how it should be. It's the job of the technical people to deal with the technicalities, so to me, it seems like everything is working properly.

Still a nasty, messy problem, though.

Can we instead arrange sunlight for 12 hours a day, all year long? That would suit me well.

You can live on the equator, where that's true. It's hellishly hot and miserable, but if that's what you'd like it's achievable.

Many equatorial cities are at a high elevation for this reason.

Also, non-intuitively the equator is not the hottest area of the planet, but rather the tropics (+/- 23 degrees), so you can expect it to be merely hot.

I wouldn't mind living in Singapore

Seems like it would be simple enough to achieve this by altering the number of minutes in an hour depending on the time of year.

I'm for it.

> Seems like it would be simple enough to achieve this by altering the number of minutes in an hour depending on the time of year.

Or just altering the length of the civil second over the course of the year. So a minute would be 60 seconds and an hour would be 60 minutes year-round, but the daytime civil second would be short in the summer night and long in summer days, and vice-versa in the winter.

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.)

In Russia there was all year DST since 2011 until 2014 (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.

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 :)

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.

Now it all makes sense. I adopt your position. Thanks for disabusing me of my ignorance.

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.

Growing up in Tromsø, I find little use for it. Sun's up two months straight in summer, and two months in winter we got only a few hours of twilight. And the rest of the year the shift is obviously quite dramatic, day to day.

After growing up like that one develops a healthy understanding of our place in the universe and that a 24 hour clock is just an abstract definition - antiquated in the space age ;)

[ed: just ftr Norway does practice DST - just seems a little silly in some parts of the country IMHO ]

You can't really do a comparison of a place so far north. I doubt there is a need for Daylight Savings Time when you have days with almost 24hr Sun/Darkness.

Alaska tried to get rid of it and change their time zone but I guess public outcry was too much.


DST has no purpose whatsoever when the days are of equal lengths, and it only helps when there's a difference between summer and winter days.

Extreme latitudes should benefit the most from any manipulation of the time of day, but they don't, which hints that this whole thing is based on bullshit.

How would an extreme latitude benefit from shifting an hour in the summer? If you're having 24hr of daylight how's switching the time going to help. The purpose of DST is to have daylight last "longer" in the evenings of the summer.

>that a 24 hour clock is just an abstract definition

Growing up at almost same latitude (Murmansk oblast), I can confirm that effect

I hate Daylight at 9PM. Kids need to go to bed because guess what? we still need to get up early and this staying up later isn't helping at all.

Blackout curtains. We ended up going to a fabric store and bying the material so we could make our own the exact size we needed. It helps a lot. (And helps keep some of the summer heat out).

We have those, but getting the kids to the bedroom is still a big challenge, especially when they are outside playing and the sun is out. "it's getting dark" doesn't work. DST is a shortsighted solution to what is not even a problem in my opinion. Why don't the people who hate sunrise at 4am get blackout curtains and leave the rest of us alone. Dealing with sun in the morning is far easier than sun at bedtime.

Why is the bedtime cue "it's getting dark" rather than "it's bedtime"?

Kids don't care about bedtime one bit.

I'm in Ireland. There's light on the north horizon at midnight. It's daylight till 10ish.

It's hell with a 6 yr old. He hasn't seen darkness in a couple of months. And the older kids still want to stay up till 11.

I agree with you. I'm in Atlanta and since we aren't too far from the border of Eastern/Central time zones it can be 930 with daylight. Contrast with Maine it's definitely a benefit, I'd hate to have darkness start so early year around.

I'm also in Atlanta and I can't stand those sunrises around 8 AM at the beginning of November right before the time changes back. Personally I think we'd be better off on Central time here - and in fact this used to be the case.

You don't need a clock to tell you it's ok to go to bed later.

You do when you work at a job that doesn't offer flexible hours.

Yeah, we should just get rid of non-DST.

I would love that.

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.

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.

I always get cognitive dissonance when I think of Egypt as an African country. Yet, it is.

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.

In France they usually prefer the term maghreb for the north-west african countries.

That doesn't include Egypt though, does it?

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."

For hysterical raisins only: Maghreb were French colonies at the time when this name took hold, whereas Egypt was British.

That's the one, thank you.

More examples on 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."

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.

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.

Obligatory link: https://qntm.org/abolish

You mean, like Swatch Internet Time from the 90s? https://en.wikipedia.org/wiki/Swatch_Internet_Time

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.

This is the way many near-eastern cultures measured day as well as most of Medieval Europe: https://en.wikipedia.org/wiki/Day#Boundaries

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?

Most people wake up with just enough time to prepare and go to work to arrive on time. They go to bed at whatever time gives them enough sleep given the time they'll wake up.

For your example, imagine it takes you 30 minutes to get ready in the morning, and 30 minutes to commute. You wake up at 8AM, leave at 8:30, arrive at 9. You get done with work at 6PM and return home at 6:30PM. You go to bed at midnight, giving you 8 hours of sleep.

Without DST, the sun rises at 5AM and wasted on you for three hours until you wake up at 8AM. You then return home at 6:30PM and benefit from 30 minutes of sunlight at home.

With DST, the sun rises at 6AM and is wasted for two hours. You get 90 minutes of sunlight at home after work.

Yes, the total amount of sunlight is the same either way, and you could rejigger your schedule to take advantage of it. But people don't.

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.

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.

> 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.

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.

Farming has no problem with DST. They work from dawn to dusk (and beyond) regardless of the clock.

Everyone parrots that DST is for farmers, as if livestock look at the clock before going about their business.

It's for factory workers. It always has been.

The reason DST exists is to shift the electric grid peak load time. As the summer base load is larger due to air conditioning during office hours, you can postpone turning on the street lights by one hour while the offices turn off their air conditioning units, avoiding bringing up peak power plants just to supply this one hour demand.

Where do you live that office buildings turn their HVAC off except for maintenance? Sure, there is less load on the system when nobody is there, but it never shuts off.

I used to work in Downtown Dallas: the building turned off their HVAC on weekends and holidays. I don't remember if they did the same for nights.

But I distinctly remember that whenever a holiday was coming up, they'd post notices on every entrance warning that the building would be closed on the holiday, pointing out that you'd have to use your badge to enter and that HVAC would be shut off all day.

Then again, that building was terrible. They operated on a shoestring budget. For example, they once cut water to the bathrooms for maintenance on a work day because they didn't want to pay more to have their maintenance people on a weekend. For another example, the elevators were scary and they were lax on maintenance: I've been stuck in them, most of my co-workers got stuck in them, and I've actually been in the elevator when it violently shook on the 6th floor and then slowly drifted to ground level. They were notoriously unprofessional, and they were literally the only property management company I've ever had to file a complaint with the city about (though it wasn't over their maintenance issues).

At least in southeast Brazil it is pretty common to turn off HVAC at night when the workers leave and turn it back on at sunrise, even large companies and buildings do this.

I work at a giant multinational company and you have to request an exception for HVAC and lighting outside office hours.

Where I've worked the AC shut off every night at 8pm and on weekends, though I think it was on 8-12am on Saturdays. Got unbearable sometimes in the summer. (California)

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.)

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

most mobile devices use network time and don't depend on internal dst rules

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.

Yeah but the local display time will be wrong for Egyptions.

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

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_countr...

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.

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.

Russia also doubled amount of DST related problems by first making DST shift permanent, then canceling it after couple of years.

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.

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.

I like the DST change for all the reasons in this article: http://www.leancrew.com/all-this/2013/03/why-i-like-dst/

> If we stayed on Standard Time throughout the year, sunrise here in the Chicago area would be between 4:15 and 4:30 am from the middle of May through the middle of July. And if you check the times for civil twilight, which is when it’s bright enough to see without artificial light, you’ll find that that starts half an hour earlier. This is insane and a complete waste of sunlight.

> If, by the way, you think the solution is to stay on DST throughout the year, I can only tell you that we tried that back in the 70s and it didn’t turn out well. Sunrise here in Chicago was after 8:00 am, which put school children out on the street at bus stops before dawn in the dead of winter.

So funny reading this after growing up at 69 degrees northern latitude ;)

Walking a couple of kilometers to school from the age of eight in darkness only lit by streetlamps. It's not so terrible.

That's not to say it's wrong; just different :)

Why not get up at 4:30am between May and July?

If you're so concerned about children ending up going to school in the dark, crazy idea, make school start later.

So, with DST, the sunrise variance goes from 4 hours, to two hours, right? 5:30am in May, and 7:XX in January?

Not really. Broadly speaking, DST was introduced to conserve fuel during war time.

Personally I prefer it to be lighter in the evenings than in the morning so I prefer DST (or BST as it's known in the UK) over the winter time (GMT / UTC)

> Broadly speaking, DST was introduced to conserve fuel during war time

It was also conceived before mass air conditioning, an invention which likely makes it a carbon-producing policy.

Would it be possible to use something like DST to make peak production of solar power line up better with peak electricity demand?

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.

Frankly, I'm beginning to think that the "old system" of per-city solar timezones, defined by the time the sun is directly overhead that city, is actually preferable to the "modern" (post International Meridian Conference of 1884) system of timezones with hourly offsets.

With solar time, the timezone, and offset with every other timezone, is fixed. With the timezone system, it became a political decision, subject to constant changes as everybody tries to move into the timezone of their trading partners, or make adjustments for the time of year.

Scheduling things between geographically distant areas can, in fact, be really hard with the timezone system - e.g., the offset between New York and London is either 4 or 5 hours, and changes 4 times per year, due to the different DST schedules. Not much fun if you're trying to run, say, an airline offering transatlantic flights + US connections.

In the old days, the solar system would have been difficult to work with, if you had to use some hard-copy chart (https://upload.wikimedia.org/wikipedia/commons/thumb/0/01/Co...), and calculate things manually. These days, it would be trivial to build the functionality into devices, watches, apps, etc, on the basis of an exhaustive, static database, instead of the timezone database which needs frantic updates due to political changes.

At this point I would go so far as to say that the time zone system is an archaic hack. If we want to do things with respect to sunrise and/or sunset we can just do that and use UTC for everything else.

Note that solar time can be determined with a small algorithm based on latitude and longitude that can fit in small embedded devices. The only remaining question is; what location should be used?

An easy way to consider the combined effect of the timezone and DST is that solar noon for the western edge of the Eastern timezone is ~1:50 right now.

I think the (utter non) popularity of UTC for setting meeting times sort of points to people not being ready to switch to a single zone (they have had access to the convenience for decades).

should get rid of leap days and seconds too. let time drift slowly, and have an arbitrary length corrective "day" off for the entire world once a century. month long siesta.

The Mayans sort of did this: https://en.wikipedia.org/wiki/Haab%27#Wayeb.27

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?

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).

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

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.

Good. Let's all do this, please.

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