Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Australia/Lord_Howe is the weirdest timezone

ssoready.com

Post reply on HN
Print view View original

141–150 of 466 posts

Re: Australia/Lord_Howe is the weirdest timezone

#141

Post by ajdlinux »

twelvechairs wrote: post #30

Along with Kathmandu for weird offsets is Australian Central Western Standard Time (UTC +8:45), used in a tiny area of Australia with the largest town being Eucla (population 37). Being mainly within Western Australia (which doesn't use daylight savings) but partially within South Australia (which does use daylight savings) there has also been informal use of UTC+9:45 Historically there was also Dublin mean time (UTC…

An interesting aspect of ACWST is that it has no legal status - it's observed purely by local convention, though it's still managed to make it into tzdata.

Re: Australia/Lord_Howe is the weirdest timezone

#142

Post by arethuza »

pbmonster wrote: post #119
arethuza wrote: post #82

Earlier quoted context omitted.

"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!

Much less of an issue without clocks. Look where the sun is, remember where it is at sunrise/-set (much easier if you're outside every day) and then mentally divide the sky into segments and just ballpark it.

"Look where the sun is"

Well, maybe that was another problem with Scotland... ;-)

No wonder they built a few walls and retreated south....

Re: Australia/Lord_Howe is the weirdest timezone

#143

Post by charlieyu1 »

hhdhdbdb wrote: post #120
hprotagonist wrote: post #96

Earlier quoted context omitted.

Ethiopian time keeping is peculiar all over. https://en.wikipedia.org/wiki/Ethiopian_calendar The Ethiopian calendar has twelve months, all thirty days long, and five or six epagomenal days, which form a thirteenth month.

That no odder than Gregorian

Still not weirder than Lunar calendar

Re: Australia/Lord_Howe is the weirdest timezone

#144

Post by Ndymium »

klysm wrote: post #68
ChrisMarshallNY wrote: post #55

I’ve found the best way to deal with TZ conversions, is to use UTC as a common fulcrum. I convert the target TZ to UTC, using my local utility, then use my local TZ utility to convert from UTC to local. But I write iOS software, so I have very solid local tools at hand. It might be more problematic, on, say, a webserver. On a related note, I wrote this utility[0], some time ago. It uses the TZ map from the TZ Boundar…

UTC is generally a good idea for storing, but there are still some ways to have that bite you. If a user enters a local date time for a future event in a particular time zone, converting that to UTC could result in incorrect behavior if the timezone definition changes. It depends on if the user meant that UTC time or if they meant the local time.

It can also cause trouble if you store past events but do not store the user's local offset or timezone at the time of the event. If you aggregate these events later into a dataset of "events by hour", they may be grouped wrong (from a user's perspective) if you convert them all to the user's _current_ timezone.

Re: Australia/Lord_Howe is the weirdest timezone

#145

Post by Gormo »

imrejonk wrote: post #39

I find it slightly ironic that a blog that’s educating (and entertaining) us on time and timezones does not itself mention when its blogposts were published, at least on mobile. This one appears to have been published in the summer of 2024.

I figured I'd check the RSS feed to see the timestamp there, only to discover that this "blog" doesn't even have a feed!

Re: Australia/Lord_Howe is the weirdest timezone

#146

Post by imrejonk »

ajdlinux wrote: post #137
imrejonk wrote: post #39

I find it slightly ironic that a blog that’s educating (and entertaining) us on time and timezones does not itself mention when its blogposts were published, at least on mobile. This one appears to have been published in the summer of 2024.

> This one appears to have been published in the summer of 2024. "Summer" in certain parts of the world, at least.

Sharp!

Re: Australia/Lord_Howe is the weirdest timezone

#147

Post by IggleSniggle »

hhdhdbdb wrote: post #120
hprotagonist wrote: post #96

Earlier quoted context omitted.

Ethiopian time keeping is peculiar all over. https://en.wikipedia.org/wiki/Ethiopian_calendar The Ethiopian calendar has twelve months, all thirty days long, and five or six epagomenal days, which form a thirteenth month.

That no odder than Gregorian

It's not odd as in a more unusual system, but odd in that it is widely incompatible with the calendar of most of the world, but still official calendar. Kinda like the Kodak calendar (which was instead 13 28-day months (364 days), and iirc does the off-day adjustments over the corporate winter holiday...actually pretty reasonable)

Re: Australia/Lord_Howe is the weirdest timezone

#148

Post by sgarland »

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).

Tangentially, Debian’s vixie-cron did / does handle DST, but it did not handle TZ changes [0], as I discovered.

[0]: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1019716

Re: Australia/Lord_Howe is the weirdest timezone

#149

Post by IgorPartola »

I know this is a popular sentiment here but it bears repeating: timezones need to go away.

Time according to timezones measures the position of the sun. Except when we clearly decide with daylight savings time that we don’t care about the position of the sun, we just want it to be a certain time.

When the sun is directly over NYC it is usually 1pm or 2pm, depending on time of year, but 5pm or 6pm in London. Why? Are these events happening at different times? No, they are happening at the same time. Why do we use a different number for them?

Your “time zone” may decide that generally the workday is from 14:00 to 22:00. Why not? We already have second and third shift workers, so the idea of 9-5 is dead anyways.

When I schedule a meeting with someone in Tokyo and I am in NYC, is the meeting not happening at the same time? Wouldn’t it be easier to say “let’s do it at 13:00”? We still would need to figure out if people are awake and at work but we have to do that now while also figuring out daylight savings, so not only time but day of the year matters.

Heaven forbid you schedule a meeting or an event or a delivery or a stock trade and your time zone gets helpfully updated after you schedule the thing but before it happens. Better hope all the processes and software get that right or else!

And here is my favorite example I recently encountered: what is the speed of federal laws in the US? Say the tax brackets are rewritten for 2025, starting “January 1”. Cool, so if you work the NYE shift from 8pm to 4am in Chicago, is it the DC timezone that matters for your taxes? The local? If cannabis is legalized starting at midnight but you get arrested for possession at 11pm the day before in LA are you wrongfully detained or did you miss it by one hour?

Timezones are 19th century thinking. We can do better.

Re: Australia/Lord_Howe is the weirdest timezone

#150

Post by flippyhead »

fouronnes3 wrote: post #103
dalmo3 wrote: post #61

Earlier quoted context omitted.

You forgot that UTC (or timekeeping in general) itself is a diff.

Oh that's a great point! We have achieved diff^5 at last! Now that I think of it, we could even stretch it one more level. In practice UTC is "realized" as a "best of" diff to atomic clocks in labs around the world, which are themselves diff against a fixed time point, as you pointed out. So that realization technically changes when the official UTC bulletin[1] is published by BIPM. So diff^6! [1] https://www.bipm.or…

Yes, but, it's always 5 o'clock somewhere, amiriiight??
Post reply on HN