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.
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.
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?
> 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).
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.
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)
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.
> 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.
I read a good argument in favour of senary on the basis of divisibility. It has nicer properties than base 12 for that.
Personally for time I don't find the convenience of its divisibility to remotely outweigh the inconvenience for addition and subtraction of using a base different to the way we count.
Whatever base we use for counting, and I can imagine arguments for senary decimal duodecimal binary or trinary, we should use the same base for counting time.
That's why my time system https://kybernetikos.github.io/UIT/ rotates the clock depending on your GPS location.
The idea is that the numeric time is the same anywhere in the world but your clock is displayed with solar midday directly up and solar midnight directly down.
It explicitly intends that each solar day is split into 10 which is then subdivided into 100 and then again. This makes an ergonomic system for human usage although the fact that its time periods vary according to the day mean its not appropriate for science and engineering where consistency and accuracy are more important.
Doing away with time zones means arranging international meetings and travel is easier. Putting a full day on one click face lets you draw on the sun rise and set times and also lets you draw a days worth of appointments on the face. Since it's base ten addition and subtraction are trivial.
This seems to ignore latitude shifts through the year. Why should solar days affect your day? I'm quite OK to wake up at 8am in the dark, and not so much at 4.30am in light. We were not all born on the equator.
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...
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.
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.
There is probably a lot of philosophy/linguistics/neuroscience to do, but there is a difference between habit and addiction. Addiction seems like a toxic shortcut to get what you want out of life, even if the "addiction" is to a benign behavior like sleep schedule.
For me, it's the perceived indefinite time alone and undisturbed after everyone else went to sleep. I feel better late at night than early in the morning, because in the latter case, I feel constant pressure of free time running out as the world around me wakes up - whereas late at night, I'm limited only by how tired I am.
> 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
Someone like you is why daylight savings time was invented originally.
I must be an evening person too because I used to think I was opposed, and then I looked at the graph of sunrise and sunset times over the year and realized what summer looks like without daylight savings, we'd waste half the sunlight before most people wake up.
That's definitely an option, if enough people want it. It would keep things lighter in the winter evenings. The major downside would be sunrise after 9:00am in the winter, so waking up, getting ready, breakfast, and commuting all in the dark.
* I wonder if people in the Arctic region, like Greenland, Iceland, Finland & Svalbard just roll their eyes when Americans talk about DST? ;)
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.
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.
> 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.
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.
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.
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.
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.
39 comments
[ 2.8 ms ] story [ 81.0 ms ] threadAnother 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_...
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.
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?
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).
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.
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)
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.
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.
Whatever base we use for counting, and I can imagine arguments for senary decimal duodecimal binary or trinary, we should use the same base for counting time.
It explicitly intends that each solar day is split into 10 which is then subdivided into 100 and then again. This makes an ergonomic system for human usage although the fact that its time periods vary according to the day mean its not appropriate for science and engineering where consistency and accuracy are more important.
Doing away with time zones means arranging international meetings and travel is easier. Putting a full day on one click face lets you draw on the sun rise and set times and also lets you draw a days worth of appointments on the face. Since it's base ten addition and subtraction are trivial.
Anyway the numeric value is the same everywhere so it doesn't affect your time, it just affects the way your clock face is drawn.
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...
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.
Someone like you is why daylight savings time was invented originally.
I must be an evening person too because I used to think I was opposed, and then I looked at the graph of sunrise and sunset times over the year and realized what summer looks like without daylight savings, we'd waste half the sunlight before most people wake up.
https://en.wikipedia.org/wiki/Daylight_saving_time#/media/Fi...
* I wonder if people in the Arctic region, like Greenland, Iceland, Finland & Svalbard just roll their eyes when Americans talk about DST? ;)
https://en.wikipedia.org/wiki/Fundamental_theorem_of_softwar...
Although that would probably lead to a discussion about leap seconds.
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
Worth noting that the provinces have the option of following DST but choose not to.
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.
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.
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.
So add four years to all values, I presume.