Poor Man's Math

Winter time is definitely crap for western europe, but I don't know how good or bad it is for eastern: CET is used from poland to france to spain so it covers a fair bit of territory, and the difference between solar and standard time is already negative: http://blog.poormansmath.net/images/SolarTimeVsStandardTimeV2.png FWIW remaining on summer time is the recommendation.

My point is that 9AM in Tokyo and 9AM in Madrid or Virginia are vastly different in terms of "position of the sun", despite being the same longitude. http://blog.poormansmath.net/images/SolarTimeVsStandardTimeV2.png <-- this map shows the difference between clock time and solar time. Western Europe and much of the US is 2 hours behind solar time compared to Tokyo. So Tokyo is set to a 9-5, but if they want to follow the same strategy of getting to work first thing in the morning, then they should be doing 7-3, or even a bit earlier due to DST non-observance. Main point is that 9 AM means vastly different things, even counting for longitude. Standard time has become standard, in setting when people wake up, but it's far from the locally ideal situations.

DST is an issue, as is the political selection of time zones. There's a great map[1] that shows how arbitrary time zone shifts are. Even in the EU, the eastern edge of Finland is over an hour east of the center of CET, while western Spain is two hours west of it. That means that during the spring and autumn solstice, even though we have 12 hours of day and 12 hours of night, the sun over western Spain sets three hours after eastern Norway. For Norway it makes sense, most of its people live smack in CET, but for Spain it's a purely political gesture. [1] http://blog.poormansmath.net/how-much-is-time-wrong-around-the-world/

Here is a similar with NZ and friends so we can all focus on what the comment is saying instead repeating how 0.1% of the world's population isn't in the image: http://blog.poormansmath.net/images/SolarTimeVsStandardTimeV2.png I agree that we've let "what time is it" get conflated with too many other things - I'm not even sure time zones are the best answer for what people are actually looking for. Having the same time to reference across a region is best handled by UTC, it's the same everywhere. When do people in a region want to wake up and start work or how long do they want light in the afternoon? Depends how long people in that region work, how far off the equator they are & what time of year it is, and what their personal preference is. Trying to solve all of these things with zones drawn and changed in a chaotic fashion (not always in the same 1 hour increment either) overlaid with offsets of that time drawn and changed in an equally chaotic fashion seems like the worst of all options. None of these things have anything to do with what the referenced number on the clock is, we've only created more problems by trying to solve it by changing the number on the clock and it hasn't made anyone agree anymore than they did before.

That's partly because it's in the same timezone as Poland. Madrid is further west that London, but London is an hour behind. Moving Spain to permanent DST puts it on the same effective timezone as London. http://blog.poormansmath.net/images/SolarTimeVsStandardTime.png Without the DST offset, Spain much more "red" than England. It's not so much a "permeant DST" but rather a "we want to change to GMT without moving out of the CET timezone."

There's a map you of the difference between clock noon and astronomical noon: http://blog.poormansmath.net/the-time-it-takes-to-change-the-time/ Pretty interesting, and it seems to comport with my feelings when traveling to different places.

Midnight on your clock is very likely tens of minutes or even hours offset from solar midnight, let alone seconds: http://blog.poormansmath.net/images/SolarTimeVsStandardTimeV2.png

It depends where you are in your time zone. For a good chunk of the land in the US, DST is closer to solar time: http://blog.poormansmath.net/images/SolarTimeVsStandardTime.png But of course a whole lot of the population lives in the part where it's worse.

The average difference from solar time would still be larger with DST. You can find a pretty good visualization here: http://blog.poormansmath.net/images/SolarTimeVsStandardTime.png This shows the difference between solar time and standard time. By switching to DST you essentially shift the gradient to the east by an hour. Other than Greenland I can't see a timezone where that wouldn't mean that the longitude at which the difference is 0 is outside of the actual timezone.

The author is absolutely correct in claiming that the *importance* of time in a culture is... cultural. Timezones and DST are especially politically sensitive. See: https://blog.poormansmath.net/the-time-it-takes-to-change-the-time/ Same for the ideas around what is a reasonable time to sleep, eat, work. There are all sort of biases for/against early risers and owls across different societies. Sounds like you and the other commenters might have an axe to grind here.

The local time of sunrise and sunset depends not only on latitude but also on the difference between local solar time and the local time zone’s time. According to http://blog.poormansmath.net/how-much-is-time-wrong-around-the-world/, that difference can exceed 90 minutes in Spain and even over 3 hours in western China. That’s the price they pay for China having a single time zone (that apparently was introduced by Mao Zedong, to show the country was unified) And yes, not everybody likes that (https://www.nytimes.com/2016/06/17/world/asia/china-single-time-zone.h…

There are complaints about India's single timezone: * https://www.bbc.com/news/world-asia-india-47168359 However, given that India is relatively narrow east-west, the discrepancy between wall time and solar time actually isn't that bad: * https://blog.poormansmath.net/how-much-is-time-wrong-around-the-world/

Solar noon is already pretty far from clock noon for most people around the world. Time zones all but guarantee that. http://blog.poormansmath.net/how-much-is-time-wrong-around-the-world/

A couple things: - a beautiful visualization of how much drift spans across timezones: http://blog.poormansmath.net/the-time-it-takes-to-change-the-time/ - local railroad time tables back in 1857: https://twitter.com/_tessr/status/900870734238449664/photo/1

Most of the world already uses a standard time that is generally late relative to the solar time. See this map being colored mostly red, which means that the sun sets later than it "should" if we were just using solar time. http://blog.poormansmath.net/the-time-it-takes-to-change-the-time/ By contrast, standard time in the "contiguous states" is much closer to solar time. Keeping DST would bring the US closer to the rest of the world.

Relevant: How much is time wrong around the world? http://blog.poormansmath.net/how-much-is-time-wrong-around-the-world/ or, if you just want to see the map: http://blog.poormansmath.net/images/SolarTimeVsStandardTimeV2.png

I noted this at the end of my comment, but I'll elaborate: Time zones do tend to be chosen such that inhabitants are within +/- 1 hour of solar time. If you look at the map at http://blog.poormansmath.net/images/SolarTimeVsStandardTimeV2.png , a switch to permanent DST in North America would make the continent a very bright red.

> There were 4.6 million replies [to the online] consultation, 70% of which were from Germans. Germans make up around 15% of the EU population. So by this metric they've got an out-sized democratic participation in the EU by a factor of almost 5x. As seen on a solar map [1][2] Germany isn't even particularly badly impacted by this issue compared to say France or Spain. There's some truth to the saying that Germany basically runs the EU, but as results like this show mostly because they seem to be making an effort to give a crap about it and its policies. 1. http://blog.poormansmath.net/images/SolarTimeVsStandardTimeV2.png (source: http://blog.poormansmath.net/how-much-is-time-wrong-around-the-world/)

Solar noon coincides with noon for a pretty small amount of places, take a look at this map: http://blog.poormansmath.net/images/SolarTimeVsStandardTimeV2.png Only the thin stripes of white have it, for every other place solar noon is off by minutes, if not hours.

There is an interesting map[1] that shows how much the time is off in each location in the world vs solar time. Japan is indeed ahead of solar time, as opposed to many other places on their longitude. (Though perhaps not by two hours). Interestingly, many more places are behind their solar time then places that are ahead of it. [1] http://blog.poormansmath.net/how-much-is-time-wrong-around-the-world/

Looking at this map[1], it doesn't seem that bad. I mean sure, France, Spain and Benelux could move to +0, but other than that the time zones seem to match reasonably well to solar time all things considered. For example both Berlin and Rome seem to be pretty well matched. Notably it would seem like using summer time would make everything worse, shifting the time zones in wrong direction. [1] http://blog.poormansmath.net/images/SolarTimeVsStandardTimeV2.png

I thought it would be related to solar time vs. local time, but an inspection of http://blog.poormansmath.net/how-much-is-time-wrong-around-the-world/ reveals that Edinburgh's solar time would actually be around 15 minutes behind its local time.

Thanks for the picture, nice. I see it's from http://blog.poormansmath.net/the-time-it-takes-to-change-the-time/ As the picture shows, Spain and the parts of France are the extremes in the Europe, in the rest of Europe the Sun is closer to being at 12:00 (not counting DST) not too different to Tokyo. Yes, the map you link shows is that some parts of the world have wider time zones than it would allow all the people living there to have the Sun very close to 12:00. But your "Tokyo sunrise" argument is still not a good one. All the areas (and cities) in the map that are "relatively white" have Sun at the highest point around 12:00 noon. Tokyo is "relatively white." New York and LA are also "relatively white." So I still don't know what is your perspective for Tokyo being strange. Can you please explain? The dramatic example would in fact be Spain or even Argentina.

This has also been done for Italy, by Stefano Maggiolo: http://blog.poormansmath.net/on-the-distribution-of-italian-towns-by-t…

To expand a bit on why the localtime() is not enough, two factors are at play. First, the solar noon can be as much as two hours displaced from the timezone. This is basically time zone vs longitude. Second, depending on time of year and attitude you can go from having no daylight in the winter to no darkness in the summer. Solar noon details here: http://blog.poormansmath.net/images/SolarTimeVsStandardTimeV2.png

I certainly think New England should move a time-zone to the east in the winter. The least disruptive way to do that would be to get on DST one year and never get off. This solar time vs. standard time map [1] indicates that most of the world prefers to slightly bias their daylight hours to the afternoon, and I'd be happier if we joined them. [1] http://blog.poormansmath.net/how-much-is-time-wrong-around-the-world/

Think you probably mean this map - http://blog.poormansmath.net/the-time-it-takes-to-change-the-time/

From "How much is time wrong around the world?"[1] see this map shaded to show the difference between standard time and solar time: http://blog.poormansmath.net/images/SolarTimeVsStandardTime.png You can see that New York is pretty much still considered 'correct' whereas Odessa, TX is rather behind. Egregious examples worldwide include Argentina, most of Saskatchewan, Western China, most of Russia, and Eastern Greenland. [1]: http://blog.poormansmath.net/how-much-is-time-wrong-around-the-world/

> DST exists so that the sun doesn't rise around 5am. No, DST exists so the sun doesn't set around 6pm. > And that seems to be what the argument boils down to: "I don't want it bright too early". No, it's not "I", it's about "we the people", and "we the people" don't care as much about "bright too early", rather they care about "dark too early". Here is a map of the offset between solar noon and civil noon[0]. The blue places have solar noon (sun in its highest position) before their local clocks show 12h00. The red places have solar noon after their clocks show that. The white places have it about the same time. Several observations: 1. This is without DST. With DST, blue places turn red, and red places turn even more red. 2. The map is kinda outdated, the bluest most populous country -- Turkey -- moved an hour since, so now it's white at the east and red otherwise. 3. Greenland looks the size of Africa, which is a projection issue, in fact it's much smaller, and that's even before we talk about its minuscule population. 4. There are places like Recife in Brazil, where solar noon varies between 11h03 and 11h33, but they still have more than 12 hours of sunlight most of year, and never less than 11:45, so they hardly care. 5. The vast, vast majority of the world would rather have the solar noon after 12h00 -- meaning, more light in the evening than in the early morning. Santiago de Compostella has solar noon at 13h17 at the earliest and 14h40 at the latest,…