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Australia/Lord_Howe is the weirdest timezone

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Re: Australia/Lord_Howe is the weirdest timezone

#41

Post by hnbad »

LysPJ wrote: post #31

> America/Nuuk does daylight savings at -01:00 (yes, with a negative) Somewhat related: Europe/Dublin has a negative DST offset. Irish DST runs through the European winter (i.e. the opposite of the other European timezones). (More details here: https://github.com/golang/go/issues/56743#issuecomment-13157... ) Edit: To be clear: the quote is referring to a negative DST start, rather than a negative DST offset.

I think you misread that. America/Nuuk doesn't have reverse DST (which is easily solved by just switching DST and non-DST around). It starts DST at a negative offset because the offset is defined as relative to the previous day.

Re: Australia/Lord_Howe is the weirdest timezone

#42

Post by zarzavat »

squiggleblaz wrote: post #19

I kind of thing a half hour daylight savings difference instead of an hour is a pretty low bar for the weirdest timezone. Almost any of the others are weirder: Antarctica/Troll definitely sounds weirder. The Moroccan and Gazan timezones that can't be expressed by the system as it was written because at least that means that they have some different kind of a rule, even if lunar time is well known. Same with the ones…

> even if lunar time is well known

The date of Ramadan is not well known because it's based on being able to see the moon from the local position on Earth. If the sky is particularly overcast for instance, then you cannot see the moon, regardless of where the moon is.

This presents problems for implementation of the calendar into the workings of a nation state. Many countries that adopt the Islamic calendar officially use an approximation, a pre-calculated date based on the moon's predicted visibility at a particular position.

The Islamic calendar is therefore not really one calendar, but two: the observational Islamic calendar and the predicted calendar, and both have a dependence on a location from which either real observations are made, or predicted observations are made.

I don't know how Morocco or Gaza do it.

Re: Australia/Lord_Howe is the weirdest timezone

#43

Post by Epa095 »

squiggleblaz wrote: post #19

I kind of thing a half hour daylight savings difference instead of an hour is a pretty low bar for the weirdest timezone. Almost any of the others are weirder: Antarctica/Troll definitely sounds weirder. The Moroccan and Gazan timezones that can't be expressed by the system as it was written because at least that means that they have some different kind of a rule, even if lunar time is well known. Same with the ones…

> But I do agree with leap seconds: it's absolute trivia, not a useful thing for a programmer to know.

Maybe, all I know is that it was relevant for me during the first years in industry. If you work with timeseries which comes from source systems you don't 100% controll, like in many industrial settings, its important to know about them, and how they are handled upstream. Do the source do smearing, or does it just sync every X hours? Does it sync with NTP, which will smear (slew) the change, or have they implemented their own thing? Do they just run `ntpd -q` regularly?

But yeah, as I type it out I realize that most programmers probably don't work in that domain:-p

Re: Australia/Lord_Howe is the weirdest timezone

#44

Post by shultays »

hnbad wrote: post #38
IshKebab wrote: post #34

Earlier quoted context omitted.

I don't really understand how that would save energy. Did people work 7am-3pm days or something?

The idea behind DST is that it shifts working hours into daylight hours during the darker months. This would theoretically cut down on energy use for lighting during those hours. Of course offices, factories and even schools still use artificial lighting even during daylight hours. And now the energy use of artificial lighting is much lower than back when everything used filament.

Even ignoring the energy saving part, it sucks waking up and leaving for work or school while it is still dark.

A while ago Turkey switched to a different timezone and stopped doing DST for reasons and now everyone was waking up one hour early in winters. Considering how bad traffic is in larger cities that meant a lot of people will be waking up and going to work or school while it is still dark.

Re: Australia/Lord_Howe is the weirdest timezone

#46

Post by kbbgl87 »

guidedlight wrote: post #18

Nah, the weirdest time zone is Africa/Addis_Ababa, which nobody in Ethiopia follows. Instead the locals offset the time by 6 hours. So the AM cycle starts at dawn (i.e. 6am), and the PM cycle starts at dusk (i.e. 6pm). https://en.wikipedia.org/wiki/Time_in_Ethiopia

And they live 7 years in the past.

Re: Australia/Lord_Howe is the weirdest timezone

#47

Post by LysPJ »

hnbad wrote: post #41
LysPJ wrote: post #31

> America/Nuuk does daylight savings at -01:00 (yes, with a negative) Somewhat related: Europe/Dublin has a negative DST offset. Irish DST runs through the European winter (i.e. the opposite of the other European timezones). (More details here: https://github.com/golang/go/issues/56743#issuecomment-13157... ) Edit: To be clear: the quote is referring to a negative DST start, rather than a negative DST offset.

I think you misread that. America/Nuuk doesn't have reverse DST (which is easily solved by just switching DST and non-DST around). It starts DST at a negative offset because the offset is defined as relative to the previous day.

Yes, this is indeed a different situation and my comment doesn't make that clear. Thank for pointing that out. I've made an edit.

Re: Australia/Lord_Howe is the weirdest timezone

#49

Post by bradley13 »

Hard-coded yearly transitions for a particular region, because they just have to have their own, special rules? Transitioning to DST on Sunday at -01:00 (minus one o'clock)? Or at 24:00?

Honestly, the IT world has a certain amount of influence. There comes a time where we could collectively just say "no". No, you are not that special, use any of the already incredibly flexible options that you have.

Re: Australia/Lord_Howe is the weirdest timezone

#50

Post by magnio »

bradley13 wrote: post #49

Hard-coded yearly transitions for a particular region, because they just have to have their own, special rules? Transitioning to DST on Sunday at -01:00 (minus one o'clock)? Or at 24:00? Honestly, the IT world has a certain amount of influence. There comes a time where we could collectively just say "no". No, you are not that special, use any of the already incredibly flexible options that you have.

> There comes a time where we could collectively just say "no"

Well, C23 mandates a byte is 8 bits, and POSIX 2024 disallows newlines in filename, so we do exercise that right times to times.

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