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Australia/Lord_Howe is the weirdest timezone

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Re: Australia/Lord_Howe is the weirdest timezone

#81

Post by lazide »

rob74 wrote: post #76
azernik wrote: post #73

The "Asia/Jerusalem" weirdness is because Daylight Savings Time is a big church-and-state issue. Religious people want the workday to be convenient for holidays that start at sunset. This led to decades (up to the mid-'00s) where Daylight Savings was the result of annual negotiations between religious and secular parties. It often caused problems when the decision wasn't made until juuuust before the transition date.…

Reading this, and considering the limited advantages of DST (especially for a country that is relatively far to the south), I wonder why they didn't decide to scrap DST completely? Maybe they will if the EU eventually manages to do it?

If they didn’t have that to argue about, what else would they do with their spare time?

Re: Australia/Lord_Howe is the weirdest timezone

#82

Post by arethuza »

marginalia_nu wrote: post #66
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

That's very similar to how the romans conceived of time. Wonder if it's an old relic from when north africa was a bunch of provinces. https://en.wikipedia.org/wiki/Roman_timekeeping

"An hour was defined as one twelfth of the daytime"

That must have been fun for the Romans here in Scotland - an hour would be roughly two and a half time as long in winter as in summer!

Re: Australia/Lord_Howe is the weirdest timezone

#83

Post by koliber »

alexjplant wrote: post #40

Earlier this year I had to write a function to find the current local time given a US address. The naive way to do so would be via a static mapping of state to time zone but there are a few edge cases that preclude doing this; in the interest of cost and speed relative to this specific application I spent a few dollars on a CSV that maps every US ZIP code to UTC offset and whether DST is followed (among other data).…

A good approach would be to map a zip code to the named timezone (e.g. US/Eastern). Then, if you need to produce the UTC offset, apply the timezone to a date using pytz and get the offset.

The named timezone is special as it is constant. The UTC offset timezone (e.g. "-05:00") and the shorthand name (e.g. "EST") is NOT constant over time for a given location, because of daylight savings time. "US/Eastern" flips between "-05:00" and "-05:00", as well as between "EDT" and "EST".

If you ask someone what their timezone is and offer them offsets or the short names, it causes confusion for everyone.

Re: Australia/Lord_Howe is the weirdest timezone

#84

Post by vander_elst »

sethammons wrote: post #72
vander_elst wrote: post #63

I still hope that someday the whole world will run on UTC0 and there is no more time zones madness. I know the day will likely never come but I like to keep dreaming.

Some dates will change when at relatively strange times. For some, the date change will be two hours into the workday. That seems odd. And you lose some info too: if I want a 07:30 (am) meeting, is that during the working hours of my target location? With offsets, I can see that it is 12:30pm at my target location and know that I am scheduling over lunch very likely. With no timezones, how do I know what time of day…

> the date change will be two hours into the workday. That seems odd

Seconds minutes and hours can change but the day cannot?

> mental math each time

Usually meetings are setup using an app and shared calendars should actually help here, a person can have meeting slots and out of office time, that should provide the same info. logistically I don't see that much of a difference from the current situation

Re: Australia/Lord_Howe is the weirdest timezone

#85

Post by extraduder_ire »

djaychela wrote: post #29

Oddly was just reading something yesterday and it mentioned that in the UK there were years during the war where we had double DST for energy saving reasons. (although we went between 1 hour and 2 hours, so it was only really a change compared to the norm) https://www.atlasobscura.com/articles/the-extreme-daylight-s...

I thing, more helpfully, that would better sync up UK time with time on much of the continent. Quite useful if you're doing a lot of things internationally.

Re: Australia/Lord_Howe is the weirdest timezone

#86

Post by yokoprime »

entuno wrote: post #80

The time zone in Palestine is a bit weird as well: https://en.wikipedia.org/wiki/Time_in_the_State_of_Palestine They have DST, but it's not on fixed dates, the government just announces each year when it's going to start and end. Sometimes with less that a week's notice, which must cause all kinds of interesting problems for people.

Without getting deep into politics I don't understand why they would prioritize spending effort on DST at all, seems like there are plenty of other concerns.

Re: Australia/Lord_Howe is the weirdest timezone

#87

Post by jdietrich »

IshKebab wrote: post #34
djaychela wrote: post #29

Oddly was just reading something yesterday and it mentioned that in the UK there were years during the war where we had double DST for energy saving reasons. (although we went between 1 hour and 2 hours, so it was only really a change compared to the norm) https://www.atlasobscura.com/articles/the-extreme-daylight-s...

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

Yesterday in the UK, sunrise was about 7am and sunset was about 4:40pm. Electricity demand peaked at about 5:30pm, in the overlap between workplaces closing for the evening and people returning home and turning everything on. There's a straightforward case for either staying on BST (UTC+1) throughout the year, or (as was the case during WWII) using UTC+2 during summer and UTC+1 during winter, effectively bringing the UK in line with CET/CEST.

The key factor in the war was the blackout - street lighting was turned off for the duration and vehicle headlights were mostly covered over, to avoid providing easy targets for night bombing raids. This obviously hugely increased the hazards posed by the early sunsets under GMT.

https://www.timeanddate.com/astronomy/uk

https://www.energydashboard.co.uk/live

https://www.bbc.co.uk/news/articles/c0mznrv3jvmo

Re: Australia/Lord_Howe is the weirdest timezone

#88

Post by rubenv »

tankenmate wrote: post #58

"Running cron jobs on an hourly basis doesn’t in practice have very weird interactions with DST" Of course every sane person runs their default system clock on UTC and lets users pick their own local time. That way cron always does the "right thing"(TM).

That's true if you need to clean up temporary files every night or make a backup.

But what if your cronjob has an effect in the physical world, locally? E.g. open the parking gates every morning.

The world is inherently messy :-)

Re: Australia/Lord_Howe is the weirdest timezone

#89

Post by extraduder_ire »

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.

In the github repo the article links, there is a large number of comments about the Europe/Dublin time zone in the europe file, including one quote from Ulysses: https://github.com/eggert/tz/blob/7748036bace8562b9c047f368c...
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