Should probably mention my favorite, ISO 8601 - Date and time format.

Date and time values are ordered from the largest to smallest unit of time: year, month (or week), day, hour, minute, second, and fraction of second. The lexicographical order of the representation thus corresponds to chronological order, except for date representations involving negative years or time offset. This allows dates to be naturally sorted by, for example, file systems.

@Preston I bring this up in conversations at least once a week.


@juno One day I will have my crusade and burn any of the non-believers who dare use other state sponsored faux date formats.

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@Preston @juno Oh yeah that 12h stuff I don’t get either. Like, the day has 24 hours, why count to twelve twice? 😅

@irimi1 @juno AM/PM is unbelievably redundant and actually gets in the way of conversation. I don't think a lot of American's realize how many times they ask the question "AM or PM?" when someone suggests a time. I think we blank out that out because we're just so use to it. There is also a lot of "trust" in assuming others have used appropriate context if you do not mention the time with AM/PM.

In 24 hour time, it's just "See ya at 17" "ya you too bud!"

done, it's over. I'll be there at 5 PM

@Preston @juno To be fair, here in Germany people also use the 12h format a lot when they’re talking to each other, with the same kind of trust involved. But I do appreciate it a lot in textual form, e.g. in calendars or invitations.

I think I’m just gonna make that my personal convention from now on. "See you at 14."–"You mean 2 at noon?"–"Yes, 14."

@irimi1 @Preston In the Netherlands I experience people saying hours in 12-hour formats but writing them in 24- hour formats.

@juno @Preston Now that you say it, written time is also always written in 24h format in Germany.

@irimi1 @juno I guess the military spoiled me too much, 24 hour time was the only way things were done spoken and written, zero confusion about where we needed to be at what time. ISO8601 was the mandatory format for written documents, and if we were doing coordination with another base in another timezone, UTC+0 was the time we would switch to instead of wondering what time in my time is their time lol.

@Preston @juno Year day month is the worst.

Buuut my position is that in prose peeps are free to use any local traditional format. In code, I see ISO most of the time but then again they could just as easily use the epoch seconds and that’d almost be easier to deal with.

@Sandra @Preston the only reason I prefer ISO8601/RFC3339 in APIs is because it's human-readable, whereas epoch seconds (or milliseconds) is not.

Another fun date format is Julian days, used for astronomical calculations.

@ndpi @Sandra

I heard RFC3339 isn't actually ISO8601, something about deviating from it because POSIX requires a timezone offset? I don't remember

@Preston @Sandra I hadn't heard that! Searched around, found this SO answer:

Apparently negative timezone offsets are allowed in the RFC but not the ISO standard.

@ndpi @Sandra

Oh then none of it really matters unless you're super nit picky. You can still get a ISO8601 compliant date within RFC3339 they just tend to make occasional deviations. Good thread thanks for the link

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