Australia/Lord_Howe is the weirdest timezone • Hacker News Board

Re: Australia/Lord_Howe is the weirdest timezone

#441

Post by Thrymr » Thu, Oct 31, 2024, 7:09 PM UTC

svilen_dobrev wrote: post #431

kccqzy wrote: post #286

The most amusing tidbit about the tz database is that it contains an estimate of Big Bang, and it refuses to calculate timezone transitions occurring before the Big Bang. The commit message at https://github.com/eggert/tz/commit/b22d459a367f4d01b10f6f6b... says: > For example, Glib computes Sao Paulo time stamps as if Brazil's circa-1913 rules were still in effect. (Thanks to Leonardo Chiquitto for reporting the bug.…

There used to be a long manpage about linux/unix `date` and what dates meant in the past - with examples of 15 century and so. Talking about some king who liked some week/month and decreed it must be repeated, and another who disliked some week and scratched it off the calendar.. It was very eye-opening reading. But i can not find it anymore. Anyone has an idea ? Is it gone completely?

man cal:

       Two different calendar systems are used, Gregorian and Julian.
       These are nearly identical systems with Gregorian making a small
       adjustment to the frequency of leap years; this facilitates
       improved synchronization with solar events like the equinoxes.
       The Gregorian calendar reform was introduced in 1582, but its
       adoption continued up to 1923. By default cal uses the adoption
       date of 3 Sept 1752. From that date forward the Gregorian
       calendar is displayed; previous dates use the Julian calendar
       system. 11 days were removed at the time of adoption to bring the
       calendar in sync with solar events. So Sept 1752 has a mix of
       Julian and Gregorian dates by which the 2nd is followed by the
       14th (the 3rd through the 13th are absent).

https://man7.org/linux/man-pages/man1/cal.1.html

Re: Australia/Lord_Howe is the weirdest timezone

#442

Post by svilen_dobrev » Thu, Oct 31, 2024, 9:23 PM UTC

Thrymr wrote: post #441

svilen_dobrev wrote: post #431

Earlier quoted context omitted.

There used to be a long manpage about linux/unix `date` and what dates meant in the past - with examples of 15 century and so. Talking about some king who liked some week/month and decreed it must be repeated, and another who disliked some week and scratched it off the calendar.. It was very eye-opening reading. But i can not find it anymore. Anyone has an idea ? Is it gone completely?

man cal: Two different calendar systems are used, Gregorian and Julian. These are nearly identical systems with Gregorian making a small adjustment to the frequency of leap years; this facilitates improved synchronization with solar events like the equinoxes. The Gregorian calendar reform was introduced in 1582, but its adoption continued up to 1923. By default cal uses the adoption date of 3 Sept 1752. From that dat…

no, not that. It was like 5-10 full pages, talking about history, mostly western european but not only..

Re: Australia/Lord_Howe is the weirdest timezone

#443

Post by dublin » Thu, Oct 31, 2024, 10:20 PM UTC

Despite having 4 of the 10 largest cities in the US, no Texas (or other Southern) city rates a listing in the zoneinfo file, so we're stuck having to pick Chicago, which is so far away (~1000 miles from Austin, in the middle of the state), that many people in the Southern US aren't necessarily certain what timezone Chicago is even in.

(The #10 slot varies according to source, but in general, Houston #4, San Antonio #7, Dallas #9, Austin #10. Fort Worth is nearly tied with Austin. Some sources claim Jacksonville, FL is #10, but they must be wrong...) :-)

Re: Australia/Lord_Howe is the weirdest timezone

#444

Post by BenjiWiebe » Thu, Oct 31, 2024, 10:23 PM UTC

psychoslave wrote: post #425

mywittyname wrote: post #243

Earlier quoted context omitted.

This would lead to a monumental amount of confusion. The primary time keeping device in my house is the clock on my stove; I wear old school watches a lot; and most of my cars are old and have old clocks in them. I can't be the only one, so multiply this by at least a few million other people in America alone. Sure, you can tell everyone they need to ditch dumb clocks and replace them with internet-enabled smart cloc…

More than one car per individual seems already such a waste but multiplying this at million people level, is that a real thing in USA or are you just extrapolating in your own social bubble? I mean, I must admit that I had the thought that this was just a troll that leverage on gross exaggeration of some American stereotypes, but actually I just can't decide if you are plain serious about these statements.

I have two cars (just for me, not family). Paid about $6k in total for them. You can have multiple cars without being in any particular social class

Re: Australia/Lord_Howe is the weirdest timezone

#445

Post by dublin » Thu, Oct 31, 2024, 10:30 PM UTC

xeromal wrote: post #293

nerdponx wrote: post #249

Earlier quoted context omitted.

What makes it more logical? The wheel turns all the same no matter where you mark the beginning. In the Northern hemisphere, there's actually something nice about starting the year in the dead of winter: it feels like the year is born in the spring and then dies away the following winter, not unlike a lifetime.

March should be the 1st month then I'd think. I'm pretty sure that's how the roman calendar worked. War started in spring.

March was the beginning of the year not all that long ago.

That's why there frequent confusion about George Washington's birthday, along with other historical dates of that era: The New Year started in March when he was born, but changed to January during his lifetime (The British Empire switched in 1752). So being born in February, there's an ambiguity about the year, unless you specify which calendar you mean:

"George Washington was born on February 22, 1732, according to the Gregorian calendar. However, when he was born, the Julian calendar was in use, which would have placed his birth on February 11, 1731."

Re: Australia/Lord_Howe is the weirdest timezone

#446

Post by Gormo » Fri, Nov 01, 2024, 12:34 AM UTC

crazygringo wrote: post #164

Gormo wrote: post #139

Earlier quoted context omitted.

The logical conclusion of going down that route would be to dispense with the concept of time zones altogether, and just revert to using local solar time.

Which would make scheduling Zoom meetings or even just phone calls hell. Especially when everyone's half-hour blocks are misaligned with each other's so you can't even stack meetings efficiently.

I figure everyone would just use local time locally, and unadjusted UTC for everything else.

Re: Australia/Lord_Howe is the weirdest timezone

#447

Post by NoInkling » Fri, Nov 01, 2024, 4:44 AM UTC

maxwell wrote: post #429

schoen wrote: post #414

Earlier quoted context omitted.

Don't you get the "it's already tomorrow for half the world" problem in place of the "it's still yesterday for half the world"?

No, not with UTC-12 (all positive offsets) or UTC+12 (all negative offsets). Any other anchor time zone creates separate days, i.e. positive and negative offsets.

What happens if a country that's currently at the new UTC-12 anchor wants to move back an hour under that system? Are they forced to "wrap around" and move to the next day instead? Or do you move the anchor itself back (to UTC-13) just to accommodate them?

Re: Australia/Lord_Howe is the weirdest timezone

#448

Post by NoInkling » Fri, Nov 01, 2024, 4:56 AM UTC

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).…

Yeah you gotta watch out for those "Etc" identifiers, especially if you were thinking about exposing all the identifiers to your users wholesale. The file for them has this comment:

> POSIX has positive signs west of Greenwich, but many people expect positive signs east of Greenwich. For example, TZ='Etc/GMT+4' uses the abbreviation "-04" and corresponds to 4 hours behind UT (i.e. west of Greenwich) even though many people would expect it to mean 4 hours ahead of UT (i.e. east of Greenwich).

Re: Australia/Lord_Howe is the weirdest timezone

#449

Post by bena » Fri, Nov 01, 2024, 1:02 PM UTC

maratc wrote: post #438

bena wrote: post #437

Earlier quoted context omitted.

All the schools around where I live start between 7 and 8, which means kids are waiting for busses and walking between 6 and 7. Sunrise will be at 7:12 tomorrow. Sunrise would be around 8am at the latest if we kept DST year-round. There is less sun during the winter. That is how it works. Just in general. Also, whenever we try "year-round DST" we go back to "spring-forward"/"fall-back" because it sucks. Everyone says…

I don't know if you follow my argument, which is: > DST actually makes most sense in 30-40 degrees of latitude. I am not arguing for having "year-round DST", nor for not having any DST at all. All I'm saying is this: at 50th parallel, there's plenty of daylight in the summer, and so: people should just figure out what to do in the winter -- and stick with it all year round. At 25th parallel, there's not much variance…

Summer daylight is not scarce. Between the 30th and 40th parallel is the bottom half of the United States.

DST exists so that the sun doesn't rise around 5am. And that seems to be what the argument boils down to: "I don't want it bright too early".

The sun is going down around 8pm during DST on the 30th.

If you're arguing to keep doing what we're doing, you've managed to have an even wronger opinion than getting rid of Standard Time.

Re: Australia/Lord_Howe is the weirdest timezone

#450

Post by maxwell » Fri, Nov 01, 2024, 2:43 PM UTC

NoInkling wrote: post #447

maxwell wrote: post #429

Earlier quoted context omitted.

No, not with UTC-12 (all positive offsets) or UTC+12 (all negative offsets). Any other anchor time zone creates separate days, i.e. positive and negative offsets.

What happens if a country that's currently at the new UTC-12 anchor wants to move back an hour under that system? Are they forced to "wrap around" and move to the next day instead? Or do you move the anchor itself back (to UTC-13) just to accommodate them?

Nothing to prevent sovereign countries from declaring to be on different day if they want to.

The BIT anchor would not be changed for political reasons, unless approved by residents of Baker Island.