3 ms·

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:

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 that are in Apple's naughty list because they're transitions the day before some day - again, not very weird, but at least it's weird enough to break things. But I do agree with leap seconds: it's absolute trivia, not a useful thing for a programmer to know. Your computer smears them and you don't even know when they happened. You could completely forget them. Except that countries transitioned from ignoring leap seconds to considering them, so the switch in Australia from "GMT+x" to "UTC+x" a couple of decades ago was the transition from ignoring leap seconds to incorporating them. The fact that this is almost universally ignored is probably for the better.

michaelt 2y ago
> But I do agree with leap seconds: it's absolute trivia, not a useful thing for a programmer to know. By and large, I agree with this. But I've always found it a bit funny when a large organisation [1] says "our servers have sub-millisecond timing accuracy, thanks to GPS synchronization and these PCIe rubidium atomic clock cards we've developed" while at the same time saying [2] "we smear leapseconds over the course of a day, in practice it doesn't matter if a server's time is off by ±0.5 seconds" [1] https://engineering.fb.com/2021/08/11/open-source/time-appliance/ https://engineering.fb.com/2021/08/11/open-source/time-appli... [2] https://engineering.fb.com/2020/03/18/production-engineering/ntp-service/ https://engineering.fb.com/2020/03/18/production-engineering...
- growse 2y ago
  The thing that super accurate timestamps buys you is common agreement across your infrastructure as to what the time is. This basically makes distributed systems work faster/better/whatever. The relation between that time and what the rest of the world thinks the time is is actually less relevant.
- knallfrosch 2y ago
  And then you validate against Microsoft's default `ClockSkew` of 5 minutes.
- zokier 2y ago
  I think the irony comes to full circle when you then use `unsmear` library to reverse the leap smearing in ntp https://github.com/google/unsmear https://github.com/google/unsmear
zarzavat 2y ago
> 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.
- pavel_lishin 2y ago
  > 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. Note to self, look up what Islamic scholars think should be done about Ramadan on a moon base.
  - School-Cotton 2y ago
    Not quite a moon base, but for Muslims on the ISS: > the Malaysian government called a gathering of 150 Islamic legal scholars, scientists, and astronauts to create guidelines for Dr. Shukor. The scholars produced a fatwa, or non-binding Islamic legal opinion, intended to help future Muslim astronauts, which they translated into both Arabic and English. They wrote that in order to pray, Muslims in space should face Mecca if possible; but if not, they could face the Earth generally, or just face “wherever.” To decide when to pray and fast during Ramadan, the scholars wrote, Muslims should follow the time zone of the place they left on Earth, which in Dr. Shukor’s case was Kazakhstan. To prostrate during prayer in zero gravity, the scholars stated that the astronaut could make appropriate motions with their head, or simply imagine the common earthly motions. I’m not an Islamic scholar (or a Muslim at all), so this is just speculation, but my guess is that if it were a permanent settlement, with people being born and living their whole lives on the moon base (so “where they left earth from” is not meaningful), they’d probably just settle on one permanent Earth time zone to follow; presumably either that of Mecca, or that of whatever country on Earth (if any) owns the base.
Epa095 2y ago
> 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
jiri 2y ago
Antarctica/Troll is not that weird. Really they use just two times: Cape Town time during short summer and Norway time otherwise. Unfortunately, Norway time happens to have DST ;-)
jdietrich 2y ago
Leap seconds are generally trivia, but they become absolutely crucial in applications where multiple parties must be in exact agreement about chronology - the obvious example being financial transactions. A lot of markets were closed for the leap second and many banks still suspend all transactions during any change of local time to mitigate the risk of error. Even in applications where we don't particularly care, there have been a surprisingly large number of leap second-related bugs. CGPM have decided to abolish the leap second for good reason. https://en.wikipedia.org/wiki/Leap_second#Other_reported_software_problems_associated_with_the_leap_second https://en.wikipedia.org/wiki/Leap_second#Other_reported_sof...
- Tor3 2y ago
  And when processing satellite data.. if you're not in agreement of the time, that one second error results in a ~7km geographical error for your typical polar orbit weather satellite.
Izkata 2y ago
> I kind of thing a half hour daylight savings difference instead of an hour is a pretty low bar for the weirdest timezone. Especially when, even disregarding the ones with special rules, there's a couple that are 45 minutes off.
madcaptenor 2y ago
Came here looking for Troll - as far as I know it's the only one to have winter daylight savings time. Also it gets extra points for the name.

michaelt 2y ago

> But I do agree with leap seconds: it's absolute trivia, not a useful thing for a programmer to know. By and large, I agree with this. But I've always found it a bit funny when a large organisation [1] says "our servers have sub-millisecond timing accuracy, thanks to GPS synchronization and these PCIe rubidium atomic clock cards we've developed" while at the same time saying [2] "we smear leapseconds over the course of a day, in practice it doesn't matter if a server's time is off by ±0.5 seconds" [1] https://engineering.fb.com/2021/08/11/open-source/time-appliance/ https://engineering.fb.com/2021/08/11/open-source/time-appli... [2] https://engineering.fb.com/2020/03/18/production-engineering/ntp-service/ https://engineering.fb.com/2020/03/18/production-engineering...

growse 2y ago
The thing that super accurate timestamps buys you is common agreement across your infrastructure as to what the time is. This basically makes distributed systems work faster/better/whatever. The relation between that time and what the rest of the world thinks the time is is actually less relevant.
knallfrosch 2y ago
And then you validate against Microsoft's default `ClockSkew` of 5 minutes.
zokier 2y ago
I think the irony comes to full circle when you then use `unsmear` library to reverse the leap smearing in ntp https://github.com/google/unsmear https://github.com/google/unsmear

zarzavat 2y ago

> 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.

pavel_lishin 2y ago
> 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. Note to self, look up what Islamic scholars think should be done about Ramadan on a moon base.
- School-Cotton 2y ago
  Not quite a moon base, but for Muslims on the ISS: > the Malaysian government called a gathering of 150 Islamic legal scholars, scientists, and astronauts to create guidelines for Dr. Shukor. The scholars produced a fatwa, or non-binding Islamic legal opinion, intended to help future Muslim astronauts, which they translated into both Arabic and English. They wrote that in order to pray, Muslims in space should face Mecca if possible; but if not, they could face the Earth generally, or just face “wherever.” To decide when to pray and fast during Ramadan, the scholars wrote, Muslims should follow the time zone of the place they left on Earth, which in Dr. Shukor’s case was Kazakhstan. To prostrate during prayer in zero gravity, the scholars stated that the astronaut could make appropriate motions with their head, or simply imagine the common earthly motions. I’m not an Islamic scholar (or a Muslim at all), so this is just speculation, but my guess is that if it were a permanent settlement, with people being born and living their whole lives on the moon base (so “where they left earth from” is not meaningful), they’d probably just settle on one permanent Earth time zone to follow; presumably either that of Mecca, or that of whatever country on Earth (if any) owns the base.

Epa095 2y ago

> 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

jiri 2y ago

Antarctica/Troll is not that weird. Really they use just two times: Cape Town time during short summer and Norway time otherwise. Unfortunately, Norway time happens to have DST ;-)

jdietrich 2y ago

Leap seconds are generally trivia, but they become absolutely crucial in applications where multiple parties must be in exact agreement about chronology - the obvious example being financial transactions. A lot of markets were closed for the leap second and many banks still suspend all transactions during any change of local time to mitigate the risk of error. Even in applications where we don't particularly care, there have been a surprisingly large number of leap second-related bugs. CGPM have decided to abolish the leap second for good reason. https://en.wikipedia.org/wiki/Leap_second#Other_reported_software_problems_associated_with_the_leap_second https://en.wikipedia.org/wiki/Leap_second#Other_reported_sof...

Tor3 2y ago
And when processing satellite data.. if you're not in agreement of the time, that one second error results in a ~7km geographical error for your typical polar orbit weather satellite.

Izkata 2y ago

> I kind of thing a half hour daylight savings difference instead of an hour is a pretty low bar for the weirdest timezone. Especially when, even disregarding the ones with special rules, there's a couple that are 45 minutes off.

madcaptenor 2y ago

Came here looking for Troll - as far as I know it's the only one to have winter daylight savings time. Also it gets extra points for the name.