7 ms·

How much is time wrong around the world? (2014)

80 points by tempodox 8y ago

jihadjihad 8y ago
This sort of thing is always interesting to me. I love how by using the analemma and the equation of time you can figure out the times of sunrise/sunset anywhere on the planet for any time of the year [1]. Another interesting thing to read about is the problem of longitude, it's amazing how clever we've had to be to solve such problems in practice. In Florence there is a Galileo museum which showcases some of his ideas on how to compute longitude, namely by using the orbits of Jupiter's moons as a sort of universal clock to make the calculation possible. [1] https://en.wikipedia.org/wiki/Analemma#Times_of_sunrise_and_sunset https://en.wikipedia.org/wiki/Analemma#Times_of_sunrise_and_...
athenot 8y ago
Is it really desireable to have the apogee of the sun be 12:00? Maybe yes maybe no: I don't know. Most businesses work ~3 hours in the morning and ~5 in the afternoon. From a thermal perspective, there's an inertia and an accumulation effect so the hottest part of the day is around 5PM, not noon. There may be times when we want to maximise whatever heat available, or conversely avoid as much heat as possible. But in the end, I think it evens out as the culture will simply adjust to what works best for most people, and not really care about lining up to neat numbers.
- zhte415 8y ago
  Interesting... the hottest part of the day in what I've experienced, in terms of thermal accumulation, is around 1-3pm. But I've usually lived on the coast or within 100km of it; the sea works as a huge normaliser for intraday temperature. When several thousand kilometers inland for the first time, the hot days and cold nights were stark, despite the average temperature being about the same. Do you live significantly away from a very large body of water?
  - Retric 8y ago
    It's also latitude dependent. The amount of sunlight you get at 4:30pm also depends on time of year and time zone, etc.
- phyzome 8y ago
  I like being able to tell what time it is by looking at the Sun's position in the sky. That's easier if solar noon lines up to within an hour.
- Izkata 8y ago
  > Most businesses work ~3 hours in the morning and ~5 in the afternoon. Don't forget about lunch! I think most people around here take it between 12:00 and 1:30, making it more like ~3 hours in the morning and ~3.5-4 hours in the afternoon (depending on how long their lunch is).
- contravariant 8y ago
  I can't really come up with a reason why one time zone would be more useful than any other, except that apart from some very rare circumstances it's really not desirable to change.
MajorSauce 8y ago
That was a great read, thanks! Made me wonder what other thing our civilization could consider starting back from scratch to adjust to our modern ways of living. For example, do we really need time to be set as this 365.25d/24h/60m/60s system? We could have something more convenient/modern/metric? Same for days of the week and daylight saving time. I know it would be absolutely impractical and costly, but I like to entertain the idea of adopting a better system.
- sharpercoder 8y ago
  https://en.wikipedia.org/wiki/Swatch_Internet_Time https://en.wikipedia.org/wiki/Swatch_Internet_Time
- dannypgh 8y ago
  365.25 is a ratio- the number of rotations of the earth per revolution. In a real sense, it comes from our solar system. If you shy away from it, any given point in your year's calendar will drift in terms of seasons. You see this in the around 354 day Hijri calendar, for instance. (Edited: removed claim 365.25 is unitless. The unit is rotations/revolution)
- martin-adams 8y ago
  Well, it's hard to change the number of solar days it takes to go around the sun one full revolution. Anything different and we'd see the seasons shift. As for number of hours in a day. 24 is very divisible which is better than say 10. You can divide it into 1, 2, 3, 4, 6, 8, 12, 24 without fractions. As for 60 minutes and 60 seconds, these again are very divisible: 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, and 60. The more interesting question, should we have chosen base 12 instead of base 10. It would of course be harder to count using your fingers.
  - JFFalcon 8y ago
    > It would of course be harder to count using your fingers. No necessarily. 4 fingers * 3 knuckles per finger make 12, so you can count in base-12 using only 1 hand. I think the Sumerians (?) used that * 5 fingers on the other hand to count in base-60, resulting in our base-60 time system.
Aardwolf 8y ago
As an evening person, personally I find it more optimal if it stays light until later in the evening, and less light is wasted on morning times like 7am But now that I think about it, maybe moving time like that also moves around when other people will be awake/asleep. So what actually defines an evening person? -a relationship between when it's light and when it's dark? -a relationship between when other people are awake and asleep and schedules like typical working hours (a desire to be awake after others went to bed, as opposed to a desire to be awake before others get up in the morning) -a relationship to the 24 numbers assigned to certain times of the day? I'm an evening person but especially in winter would like more light in the evening. So I guess what I really prioritize is being awake after other went asleep, instead of when it's light/dark, even if it makes me miss out on some light that I would like to see. Or maybe my biological clock thinks differently than what my mind wants...
- colechristensen 8y ago
  From what I have experienced, some people have a strong cognitive bias towards the numbers on a clock, for example, needing to look at a clock in bed to decide if they are still tired. (or worse getting up happy and awake to be devastated to learn it is early morning after a few minutes) People tend to identify themselves as a certain way, and those ideas have a strong impact on behaviors and desires. Of course it's silly to link how tired you feel to a clock, but it happens! If you'd like more light towards the end of your day wake up earlier! (and sleep earlier) Try to realize that when you feel you want to be awake and asleep might have a lot more to do with an image of yourself you have attached to instead of any biological cause.
  - staplers 8y ago
    needing to look at a clock in bed to decide if they are still tired You make a great point here and it almost reminds me of addict behavior. I would be curious to see which pathways are illuminated in the brain with regards to 'checking the time' during resting hours.
    - kzrdude 8y ago
coding123 8y ago
There will be 45 suggestions to change how we track time in this thread.
- colechristensen 8y ago
  My suggestion is people try to put much more distance between themselves and time.
  - s3m4j 8y ago
    >"We can solve any problem by introducing an extra level of indirection." https://en.wikipedia.org/wiki/Fundamental_theorem_of_software_engineering https://en.wikipedia.org/wiki/Fundamental_theorem_of_softwar...
- contravariant 8y ago
  Unix time for everyone! Although that would probably lead to a discussion about leap seconds.
drngdds 8y ago
Very tangential, but it's pretty annoying how so many articles on the internet unnecessarily make things bold.
tzs 8y ago
What is going on with Argentina? It straddles what would be UTC-4 and UTC-5, so one would expect it to be in one of those time zones, or to be a two time zone country using both of those, but it is actually in UTC-3 (which is why it is all deep red in the map). According to Wikipedia [1]: > The first official standardization took place on 25 September 1894. The official time switched between UTC−4 and UTC−3 from 1920 to 1969, and then between UTC−3 and UTC−2 from 1974 to 1993. [...] On 7 March 1993, it was fixed at UTC−3, called Argentina Time. I can sort of see UTC-3 if they felt it was important to be in the same time zone as Brazil...but I can't even come up with a guess as to how UTC-2 was ever an option. [1] https://en.wikipedia.org/wiki/Time_in_Argentina https://en.wikipedia.org/wiki/Time_in_Argentina
- jersully72 8y ago
  I suspect it's their preference for daylight in the winter. Which currently in Buenos Aires is about 8:00 AM to 6:00 PM. Worth noting that the provinces have the option of following DST but choose not to.
chipschap 8y ago
I'm mildly surprised this discussion hasn't brought up the artificiality of daylight savings time, summer time, and whatever other names it might be called by around the world. Certainly the concept is prevalent enough. Leaving aside the arguments about saving energy (I am not knowledgeable enough to speak to that in any event), daylight savings time seems to be an enormous confusion factor, especially since (as one example) Europe and North America have different start and end dates. On one level it seems that DST is a way of patching a system that is fundamentally flawed, hence some of the very interesting suggestions in these discussions about alternative methods of timekeeping. But changing such an entrenched and widespread standard might be next to impossible.
- dahart 8y ago
  > I'm mildly surprised this discussion hasn't brought up the artificiality of daylight savings time I'm reminded of the Hitchhiker's Guide to the Galaxy: "Time is an illusion. Lunchtime doubly so." Time zones are artificial too, but the benefits of coordination outweigh the advantages of sticking to a perfect solar noon. The thing DST does pretty well is keep sunrise to within an hour of 7:00am (plus or minus, depending on location) year round. Without DST, sunrise varies by 3 hours in the US. > daylight savings time seems to be an enormous confusion factor It certainly requires people to adjust, two days a year. There is certainly some small amount of effort related to publishing calendars and having a few people forget, I suppose. At least, that used to be common before smartphones and the internet. It seems to be fading over time. But what is the enormous confusion are you referring to? It seems like these days, since nearly all clocks and phones are digital and net-connected, we could, if we wanted, have a continuously adjusting schedule. That wouldn't reduce confusion, but it's no longer crazy either.
  - prerok 8y ago
    I think that the referred confusion is the difference in applying the DST between Europe and US: Start and end dates vary with location and year. Since 1996, European Summer Time has been observed from the last Sunday in March to the last Sunday in October; previously the rules were not uniform across the European Union. Starting in 2007, most of the United States and Canada observe DST from the second Sunday in March to the first Sunday in November, almost two-thirds of the year. The problem is that if you're European (like me) and have recurring weekly meetings with US based coworkers the meetings will be shifted by an hour until the other party shifts the clock.
jameshart 8y ago
It’s interesting that while, as the author notes, the map seems to skew red overall, with more places opting for a late time zone, the few deep green areas there are are among the most heavily populated regions in the world - the northeast US, Japan, central Indonesia, coastal Brazil, Southern California. This is a typical issue with geographic visualizations. I’d be interested to see a population histogram for how many people are on late solar time vs early.
Bromskloss 8y ago
> 2014 So add four years to all values, I presume.
nicolas_t 8y ago
Having lived in Japan and China (shanghai) which are both wrong in the opposite way of Spain and lived in France and Spain, I find that living in the red zones is really much more comfortable and a lovely way to live.
chmike 8y ago
This shows how much staying with UTC time or adopt the International Atomic Time (TAI) is a false problem. As time references changed because of the telegraph and railways, computers will make us change from UTC to TAI. The question is when.

80 points by tempodox 8y ago

This sort of thing is always interesting to me. I love how by using the analemma and the equation of time you can figure out the times of sunrise/sunset anywhere on the planet for any time of the year [1]. Another interesting thing to read about is the problem of longitude, it's amazing how clever we've had to be to solve such problems in practice. In Florence there is a Galileo museum which showcases some of his ideas on how to compute longitude, namely by using the orbits of Jupiter's moons as a sort of universal clock to make the calculation possible. [1] https://en.wikipedia.org/wiki/Analemma#Times_of_sunrise_and_sunset https://en.wikipedia.org/wiki/Analemma#Times_of_sunrise_and_...

athenot 8y ago

Is it really desireable to have the apogee of the sun be 12:00? Maybe yes maybe no: I don't know. Most businesses work ~3 hours in the morning and ~5 in the afternoon. From a thermal perspective, there's an inertia and an accumulation effect so the hottest part of the day is around 5PM, not noon. There may be times when we want to maximise whatever heat available, or conversely avoid as much heat as possible. But in the end, I think it evens out as the culture will simply adjust to what works best for most people, and not really care about lining up to neat numbers.

zhte415 8y ago
Interesting... the hottest part of the day in what I've experienced, in terms of thermal accumulation, is around 1-3pm. But I've usually lived on the coast or within 100km of it; the sea works as a huge normaliser for intraday temperature. When several thousand kilometers inland for the first time, the hot days and cold nights were stark, despite the average temperature being about the same. Do you live significantly away from a very large body of water?
- Retric 8y ago
  It's also latitude dependent. The amount of sunlight you get at 4:30pm also depends on time of year and time zone, etc.
phyzome 8y ago
I like being able to tell what time it is by looking at the Sun's position in the sky. That's easier if solar noon lines up to within an hour.
Izkata 8y ago
> Most businesses work ~3 hours in the morning and ~5 in the afternoon. Don't forget about lunch! I think most people around here take it between 12:00 and 1:30, making it more like ~3 hours in the morning and ~3.5-4 hours in the afternoon (depending on how long their lunch is).
contravariant 8y ago
I can't really come up with a reason why one time zone would be more useful than any other, except that apart from some very rare circumstances it's really not desirable to change.

MajorSauce 8y ago

That was a great read, thanks! Made me wonder what other thing our civilization could consider starting back from scratch to adjust to our modern ways of living. For example, do we really need time to be set as this 365.25d/24h/60m/60s system? We could have something more convenient/modern/metric? Same for days of the week and daylight saving time. I know it would be absolutely impractical and costly, but I like to entertain the idea of adopting a better system.

sharpercoder 8y ago
https://en.wikipedia.org/wiki/Swatch_Internet_Time https://en.wikipedia.org/wiki/Swatch_Internet_Time
dannypgh 8y ago
365.25 is a ratio- the number of rotations of the earth per revolution. In a real sense, it comes from our solar system. If you shy away from it, any given point in your year's calendar will drift in terms of seasons. You see this in the around 354 day Hijri calendar, for instance. (Edited: removed claim 365.25 is unitless. The unit is rotations/revolution)
martin-adams 8y ago
Well, it's hard to change the number of solar days it takes to go around the sun one full revolution. Anything different and we'd see the seasons shift. As for number of hours in a day. 24 is very divisible which is better than say 10. You can divide it into 1, 2, 3, 4, 6, 8, 12, 24 without fractions. As for 60 minutes and 60 seconds, these again are very divisible: 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, and 60. The more interesting question, should we have chosen base 12 instead of base 10. It would of course be harder to count using your fingers.
- JFFalcon 8y ago
  > It would of course be harder to count using your fingers. No necessarily. 4 fingers * 3 knuckles per finger make 12, so you can count in base-12 using only 1 hand. I think the Sumerians (?) used that * 5 fingers on the other hand to count in base-60, resulting in our base-60 time system.

Aardwolf 8y ago

As an evening person, personally I find it more optimal if it stays light until later in the evening, and less light is wasted on morning times like 7am But now that I think about it, maybe moving time like that also moves around when other people will be awake/asleep. So what actually defines an evening person? -a relationship between when it's light and when it's dark? -a relationship between when other people are awake and asleep and schedules like typical working hours (a desire to be awake after others went to bed, as opposed to a desire to be awake before others get up in the morning) -a relationship to the 24 numbers assigned to certain times of the day? I'm an evening person but especially in winter would like more light in the evening. So I guess what I really prioritize is being awake after other went asleep, instead of when it's light/dark, even if it makes me miss out on some light that I would like to see. Or maybe my biological clock thinks differently than what my mind wants...

colechristensen 8y ago
From what I have experienced, some people have a strong cognitive bias towards the numbers on a clock, for example, needing to look at a clock in bed to decide if they are still tired. (or worse getting up happy and awake to be devastated to learn it is early morning after a few minutes) People tend to identify themselves as a certain way, and those ideas have a strong impact on behaviors and desires. Of course it's silly to link how tired you feel to a clock, but it happens! If you'd like more light towards the end of your day wake up earlier! (and sleep earlier) Try to realize that when you feel you want to be awake and asleep might have a lot more to do with an image of yourself you have attached to instead of any biological cause.
- staplers 8y ago
  needing to look at a clock in bed to decide if they are still tired You make a great point here and it almost reminds me of addict behavior. I would be curious to see which pathways are illuminated in the brain with regards to 'checking the time' during resting hours.
  - kzrdude 8y ago

coding123 8y ago

There will be 45 suggestions to change how we track time in this thread.

colechristensen 8y ago
My suggestion is people try to put much more distance between themselves and time.
- s3m4j 8y ago
  >"We can solve any problem by introducing an extra level of indirection." https://en.wikipedia.org/wiki/Fundamental_theorem_of_software_engineering https://en.wikipedia.org/wiki/Fundamental_theorem_of_softwar...
contravariant 8y ago
Unix time for everyone! Although that would probably lead to a discussion about leap seconds.

drngdds 8y ago

Very tangential, but it's pretty annoying how so many articles on the internet unnecessarily make things bold.

tzs 8y ago

What is going on with Argentina? It straddles what would be UTC-4 and UTC-5, so one would expect it to be in one of those time zones, or to be a two time zone country using both of those, but it is actually in UTC-3 (which is why it is all deep red in the map). According to Wikipedia [1]: > The first official standardization took place on 25 September 1894. The official time switched between UTC−4 and UTC−3 from 1920 to 1969, and then between UTC−3 and UTC−2 from 1974 to 1993. [...] On 7 March 1993, it was fixed at UTC−3, called Argentina Time. I can sort of see UTC-3 if they felt it was important to be in the same time zone as Brazil...but I can't even come up with a guess as to how UTC-2 was ever an option. [1] https://en.wikipedia.org/wiki/Time_in_Argentina https://en.wikipedia.org/wiki/Time_in_Argentina

jersully72 8y ago
I suspect it's their preference for daylight in the winter. Which currently in Buenos Aires is about 8:00 AM to 6:00 PM. Worth noting that the provinces have the option of following DST but choose not to.

chipschap 8y ago

I'm mildly surprised this discussion hasn't brought up the artificiality of daylight savings time, summer time, and whatever other names it might be called by around the world. Certainly the concept is prevalent enough. Leaving aside the arguments about saving energy (I am not knowledgeable enough to speak to that in any event), daylight savings time seems to be an enormous confusion factor, especially since (as one example) Europe and North America have different start and end dates. On one level it seems that DST is a way of patching a system that is fundamentally flawed, hence some of the very interesting suggestions in these discussions about alternative methods of timekeeping. But changing such an entrenched and widespread standard might be next to impossible.

dahart 8y ago
> I'm mildly surprised this discussion hasn't brought up the artificiality of daylight savings time I'm reminded of the Hitchhiker's Guide to the Galaxy: "Time is an illusion. Lunchtime doubly so." Time zones are artificial too, but the benefits of coordination outweigh the advantages of sticking to a perfect solar noon. The thing DST does pretty well is keep sunrise to within an hour of 7:00am (plus or minus, depending on location) year round. Without DST, sunrise varies by 3 hours in the US. > daylight savings time seems to be an enormous confusion factor It certainly requires people to adjust, two days a year. There is certainly some small amount of effort related to publishing calendars and having a few people forget, I suppose. At least, that used to be common before smartphones and the internet. It seems to be fading over time. But what is the enormous confusion are you referring to? It seems like these days, since nearly all clocks and phones are digital and net-connected, we could, if we wanted, have a continuously adjusting schedule. That wouldn't reduce confusion, but it's no longer crazy either.
- prerok 8y ago
  I think that the referred confusion is the difference in applying the DST between Europe and US: Start and end dates vary with location and year. Since 1996, European Summer Time has been observed from the last Sunday in March to the last Sunday in October; previously the rules were not uniform across the European Union. Starting in 2007, most of the United States and Canada observe DST from the second Sunday in March to the first Sunday in November, almost two-thirds of the year. The problem is that if you're European (like me) and have recurring weekly meetings with US based coworkers the meetings will be shifted by an hour until the other party shifts the clock.

jameshart 8y ago

It’s interesting that while, as the author notes, the map seems to skew red overall, with more places opting for a late time zone, the few deep green areas there are are among the most heavily populated regions in the world - the northeast US, Japan, central Indonesia, coastal Brazil, Southern California. This is a typical issue with geographic visualizations. I’d be interested to see a population histogram for how many people are on late solar time vs early.

Bromskloss 8y ago

> 2014 So add four years to all values, I presume.

nicolas_t 8y ago

Having lived in Japan and China (shanghai) which are both wrong in the opposite way of Spain and lived in France and Spain, I find that living in the red zones is really much more comfortable and a lovely way to live.

chmike 8y ago

This shows how much staying with UTC time or adopt the International Atomic Time (TAI) is a false problem. As time references changed because of the telegraph and railways, computers will make us change from UTC to TAI. The question is when.