It's in sort order. Even if you use it for things that don't understand dates, they sort properly because the day is the last part, month is the middle part, and year is the first part. If you include hours, minutes or seconds, the sort order is still preserved.
Speaking of things that don't understand dates, because there are no slashes, you can easily use it in file names, directories, and anything else that treats slash as a special character. In addition, if you include the time part, because it uses "T" to separate the date and time, it doesn't use a space, so once again it can be easily used anywhere where a space might cause issues.
To be fair, the time separators don't behave well on all implementations of filesystem access by filename. Need to use underscores or omit them at times.
Except I can't get behind the time part of it, personally. I can see the point of doing GMT with the offset if you're working across multiple timezones, but it's overkill for situations where you aren't.
If you work at a company where all of its offices are in the same time zone and you're time-stamping logs, then it's more expedient for understanding and placing an event in time against other things to use local time.
Unless everything is already standardized as GMT with offset I guess, but I feel like down that route lies madness.
"I got your email at 20:37:45-7:00" is a few more steps than "I got your email at 1:37PM".
It's not a big hurdle, but I try to design for the newest member on the team scrambling in panic rather than a calm cool professional already familiar with conventions.
Now, as soon as we do start dealing with multiple time zones I would just cut my custom time formatting string down to the shorthand to have the scripting language output in the full ISO 8601 format. But until then, being able to easily sort the the date properly and having the time be more human readable is a more "workable" compromise.
July 4th is a funny example cause you can say “the 4th” and everyone knows what you mean, but people also say “4th of July” to give it more importance.
That’s a lot less common for other dates, Americans aren’t commonly saying “25th of December”.
In spoken conversation it doesn't really matter. In many contexts you could probably just say "Want to go on the third?" and the person you're talking to will understand you mean August the third of this current year.
It does to me. mm-dd is not used at all in my native language and would be considered grammatically incorrect. Since English doesn't prescribe it I have no reason to fully accept it.
Note that I still prefer to write ISO 8601 dates but my spoken dates are big-endian.
Middle-endian dates like "June 15th 2046" are just bad, of course.
I commented earlier that having to say more words is inefficient, but what yiu said made me think... In other languages I know, it's basically spoken as "3rd August'... Eliminating the inefficiency. It's really more English's general inefficiency that irks me, more so than the order of the dates lol
Yes as well (Also insane) but its universally ledgable, sorts on computers easier, accomodates timezones and sub-second units. ISO-8601 should be the universal standard, and anyone who says otherwise better show up with a white paper explaining why. None of this dumb american format or javascript web form bullshit, language is about specificity, BE SPECIFIC. Unless you want to go off the rails and talk about relativity, time dialation and reference points... But thats all above my pay grade. ISO-8601 is a golden example of "good enough for normal people". Thank you for coming to my TEDtalk.
I shorthand it verbally unless I'm giving a full date, but typed, it's almost always yyyy-MM-dd HH:mm:ss (whichever part of that is relevant).
I do this because I believe it's the most logical, it sorts properly without having to use a datetime library, and it can't be confused with another system (is 12-1-2026 in the future or the past? No way to know just by looking at it).
Just shortening it to MM-dd could cause confusion with anyone not in the US so I'll typically include the year as well (also useful if I wind up having to look at old notes or emails to not have to figure out the year I meant ... Which has happened more than once ...)
Only a truly insane person would use mm-dd-yy in conversation. “Want to go to a hockey game with me ten seventeen twenty-six?” Or worse, “…oh four oh seven twenty-seven.” Pure madness.
Conversationally, mmm d yy or d mmm yy (usually just shortened to mmm d or d mmm) is where it’s at.
RFC3339 is better than ISO8601 since it doesn't allow some of the esoteric formats, and allows some useful formats that ISO8601 doesn't (like separating date and time by a space instead of by T)
For example, 2026-W32-1 is also a valid ISO8601 date: Monday on the 32nd week of 2026. That format isn't allowed with RFC3339.
yyyy/mm/dd, it's less ambiguous and it sorts nicely
Edit: so many replies suggesting using a hyphen as a separator, I'd like to compromise by using the oblique angle sign (⦧) which looks like a slash that becomes a hyphen in the middle. yyyy⦧mm⦧dd
Beat me to it, except I’d do yyyy-mm-dd because some OSes throw fits about having slashes in file names. Way better than the “Group Project-final FINAL v3 PAUL USE THIS ONE.file” versioning system that people seem to use.
ISO 8601 RFC 3339 (yyyy-mm-dd) for storing dates in software. Any format that that goes in the order of day, month, and year for conversational/presentational purposes, preferable the format is dynamic depending on the user's locale (even for those that want the month first). There now everyone is happy.
Edit: switched to RFC 3339 since it is a subset of ISO 8601 that is more strict, and I love semantics.
RFC3339 is better than ISO8601 since it doesn't allow some of the esoteric formats, and allows some useful formats that ISO8601 doesn't (like separating date and time by a space instead of by T)
For example, 2026-W32-1 is also a valid ISO8601 date: Monday on the 32nd week of 2026. That format isn't allowed with RFC3339.
Damn it I forgot about the duration part of ISO 8601 (which is also super useful and I love it). I'll amend it to RFC 3339 to be more exact in what I mean (even though the specified format should prevent the more esoteric formats).
Months are stupid anyway, lets drop them and swap for what they were supposed to represent instead: the moon phase, so today would be 216-2026-Waning Gibbous
ITT: people saying one thing is better than any other without thinking of context.
If I want to know today's date ISO 8601 isn't a good answer. And if I put stuff in folders by date then DD-MM-YYYY is a real bad way to do it.
But MM-DD-YYYY is the worst one no matter the context.
While it's confusing in a vacuum, it's also just the way we say it out loud in american English (April 20, 2026), so it's not that weird when you think about it like that.
However for countries that adopt dd-mm-yyyy, it's also completely natural to say it out loud in that way (20 April 2026).
So by that reasoning we will never end up with a universally accepted date format.
DD(First 3 of Month, All Caps)YYYY
examples: 01JAN2026, 24MAR1987,20DEC3065
This is how I had to write dates when I worked for a cGMP pharma manufacturing facility and did controlled paperwork. The idea was it was it was impossible for any mistakes when reading the date, only the days were 2 digits, the month was letters, and the year was 4 digits.
Basically all of the validated SOPs were written so that anyone could pick up the paperwork and execute the instructions, and the inverse had to be true as well anyone picking up a completed SOP should be able to read and follow everything written down, and literally every step in the process required initials and date it was executed.
Fun fact, if you fucked up and wrote something wrong or illegibly you were punished twice, once because you had to strike out the mistake, initial date the strikeout and write correctly the next time, and the second was when you get stink eyed by the QA people who have to review all the paperwork before it's scanned and logged back into documentum.
DD MON YEAR is the only one that’s not ambiguous on November tenth and the like. 10 Nov 2022 is less confusing than either 11/10/2022 or 10/11/2022 and is without a doubt never confusing.
89 Comments
red_tomato@lemmy.world · 194 pts · 5h
ISO 8601
7EP6vuI@feddit.org · 127 pts · 5h
ISO 8601
jlow@slrpnk.net · 31 pts · 5h
👆
merc@sh.itjust.works · 26 pts · 2h
As for why it's better:
raspberriesareyummy@lemmy.world · 2 pts · 43m
To be fair, the time separators don't behave well on all implementations of filesystem access by filename. Need to use underscores or omit them at times.
TootSweet@lemmy.world · 25 pts · 5h
This is the way.
davidagain@lemmy.world · 3 pts · 33m
This is the way.
mkwt@lemmy.world · 11 pts · 5h
ISO would be great, but sadly OmegaStar doesn't support ISO timestamps yet.
TrickDacy@lemmy.world · 9 pts · 3h
Wtf is an omega star?
Viking_Hippie@lemmy.dbzer0.com · 4 pts · 2h
The last star of the Greek alphabet? 🤷🏻
trem@lemmy.blahaj.zone · 10 pts · 5h
RFC 3339
trainsrkool@lemmy.ml · 5 pts · 1h
💯
wizardbeard@lemmy.dbzer0.com · 3 pts · 4h
Except I can't get behind the time part of it, personally. I can see the point of doing GMT with the offset if you're working across multiple timezones, but it's overkill for situations where you aren't.
Dookieman12@piefed.social · 7 pts · 3h
There's no way to predict how a date will be used. No reason not to be flexible. No reason to break convention.
laurelraven@lemmy.blahaj.zone · 3 pts · 4h
How so, out of curiosity?
wizardbeard@lemmy.dbzer0.com · 1 pts · 1h
If you work at a company where all of its offices are in the same time zone and you're time-stamping logs, then it's more expedient for understanding and placing an event in time against other things to use local time.
Unless everything is already standardized as GMT with offset I guess, but I feel like down that route lies madness.
"I got your email at 20:37:45-7:00" is a few more steps than "I got your email at 1:37PM".
It's not a big hurdle, but I try to design for the newest member on the team scrambling in panic rather than a calm cool professional already familiar with conventions.
Now, as soon as we do start dealing with multiple time zones I would just cut my custom time formatting string down to the shorthand to have the scripting language output in the full ISO 8601 format. But until then, being able to easily sort the the date properly and having the time be more human readable is a more "workable" compromise.
Eq0@literature.cafe · 3 pts · 3h
That’s how my brother missed a train: the linux planner used GMT while the local train company planner used assumed local time…
So I disagree
CannedYeet@lemmy.world · 1 pts · 2h
Yeah, the time part should obviously be written in Swatch Internet Time, he writes at @910.
BigDiction@lemmy.world · -4 pts · 4h
It’s great, and standard for software. But do any of y’all communicate dates like this in your personal life?
Like “want to go to a hockey game with me 2026-10-17?” As cursed as mm-dd-yy is, it feels a lot more natural in conversation.
dantel@programming.dev · 31 pts · 4h
Say when is that independence day of yours?
There is nothing 'natural' about mm/dd/yy, it is just what you are used to - end of story.
TrickDacy@lemmy.world · 3 pts · 3h
What you are used to inevitably becomes more natural for you subjectively...
BigDiction@lemmy.world · 2 pts · 2h
I knew I would eat shit for that comment.
July 4th is a funny example cause you can say “the 4th” and everyone knows what you mean, but people also say “4th of July” to give it more importance.
That’s a lot less common for other dates, Americans aren’t commonly saying “25th of December”.
Quokka@quokk.au · 11 pts · 4h
dd-mm feels completely natural to say in conversation. “Do you want to go to a X with me on the 3rd of August”
OpenStars@discuss.online · 3 pts · 3h
But... what YEAR!?!?
merc@sh.itjust.works · 2 pts · 2h
Does "August 3rd" sound unnatural to you?
In spoken conversation it doesn't really matter. In many contexts you could probably just say "Want to go on the third?" and the person you're talking to will understand you mean August the third of this current year.
Jesus_666@lemmy.world · 3 pts · 1h
It does to me. mm-dd is not used at all in my native language and would be considered grammatically incorrect. Since English doesn't prescribe it I have no reason to fully accept it.
Note that I still prefer to write ISO 8601 dates but my spoken dates are big-endian.
Middle-endian dates like "June 15th 2046" are just bad, of course.
recursivethinking@lemmy.world · 1 pts · 22m
I commented earlier that having to say more words is inefficient, but what yiu said made me think... In other languages I know, it's basically spoken as "3rd August'... Eliminating the inefficiency. It's really more English's general inefficiency that irks me, more so than the order of the dates lol
recursivethinking@lemmy.world · 1 pts · 2h
Its fine but its unnecessarily long. Its just one syllable/word but its extra.
ArmoredThirteen@lemmy.zip · 2 pts · 2h
Two words when used in a sentence. "The 3rd of August" vs "August 3rd"
lena@gregtech.eu · 7 pts · 4h
Yes (I'm insane)
Bahnd@lemmy.world · 6 pts · 3h
Yes as well (Also insane) but its universally ledgable, sorts on computers easier, accomodates timezones and sub-second units. ISO-8601 should be the universal standard, and anyone who says otherwise better show up with a white paper explaining why. None of this dumb american format or javascript web form bullshit, language is about specificity, BE SPECIFIC. Unless you want to go off the rails and talk about relativity, time dialation and reference points... But thats all above my pay grade. ISO-8601 is a golden example of "good enough for normal people". Thank you for coming to my TEDtalk.
bitchkat@lemmy.world · 7 pts · 3h
I absolutely full out dates in iso 8601 any time I'm required to sign a form.
davidagain@lemmy.world · 2 pts · 30m
I like your style. I'll start doing that, (unless a format is specified, because I'm no protocol breaker.)
laurelraven@lemmy.blahaj.zone · 5 pts · 4h
Yes, kind of.
I shorthand it verbally unless I'm giving a full date, but typed, it's almost always yyyy-MM-dd HH:mm:ss (whichever part of that is relevant).
I do this because I believe it's the most logical, it sorts properly without having to use a datetime library, and it can't be confused with another system (is 12-1-2026 in the future or the past? No way to know just by looking at it).
Just shortening it to MM-dd could cause confusion with anyone not in the US so I'll typically include the year as well (also useful if I wind up having to look at old notes or emails to not have to figure out the year I meant ... Which has happened more than once ...)
Dookieman12@piefed.social · 3 pts · 3h
There's no reason the two need to be the same. We don't talk in heximal either
lividweasel@lemmy.world · 3 pts · 3h
Only a truly insane person would use mm-dd-yy in conversation. “Want to go to a hockey game with me ten seventeen twenty-six?” Or worse, “…oh four oh seven twenty-seven.” Pure madness.
Conversationally, mmm d yy or d mmm yy (usually just shortened to mmm d or d mmm) is where it’s at.
Zikeji@programming.dev · 56 pts · 5h
I read this meme and was physically revolted and wanted to immediately down vote. Great job.
The superior date format is, of course, ISO 8601. YYYY-MM-DD.
dan@upvote.au · 15 pts · 4h
RFC3339 is better than ISO8601 since it doesn't allow some of the esoteric formats, and allows some useful formats that ISO8601 doesn't (like separating date and time by a space instead of by
T)For example,
2026-W32-1is also a valid ISO8601 date: Monday on the 32nd week of 2026. That format isn't allowed with RFC3339.https://ijmacd.github.io/rfc3339-iso8601/
gex@lemmy.world · 49 pts · 5h
yyyy/mm/dd, it's less ambiguous and it sorts nicely
Edit: so many replies suggesting using a hyphen as a separator, I'd like to compromise by using the oblique angle sign (⦧) which looks like a slash that becomes a hyphen in the middle. yyyy⦧mm⦧dd
Pudutr0n@lemmy.world · 12 pts · 5h
nerd detected
7EP6vuI@feddit.org · 5 pts · 5h
lmftfy: american nerd detected
otter@lemmy.zip · 7 pts · 4h
What's American about ISO 8601 with slashes?
Edit: typo
fartsparkles@lemmy.world · 3 pts · 4h
*ISO 8601
7EP6vuI@feddit.org · 1 pts · 3h
i don't think ISO 8601 allows slashes.
but: you are right, and i was not aware: many countries use the
/for dates: https://en.wikipedia.org/wiki/List_of_date_formats_by_country i thought this was a USA thing... thanks for the hint!Carl@anarchist.nexus · 8 pts · 4h
Beat me to it, except I’d do yyyy-mm-dd because some OSes throw fits about having slashes in file names. Way better than the “Group Project-final FINAL v3 PAUL USE THIS ONE.file” versioning system that people seem to use.
Bahnd@lemmy.world · 6 pts · 3h
HISSSSSS.
switch the slashes to dashes
[Angry ISO-8601 noises]
procrastitron@lemmy.world · 13 pts · 4h
Anyone who wants to write the millennium between the month and century loses all credibility when arguing about date formats.
YYYY-MM-DD is the only coherent date format.
deadbeef79000@lemmy.nz · 4 pts · 3h
That took me a minute to parse, but now I like it.
Grostleton@lemmy.dbzer0.com · 12 pts · 5h
I prefer ddd/yyyy, much simpler
fartsparkles@lemmy.world · 21 pts · 4h
Ah yes,
Mon/2026, perfect…Baizey@feddit.dk · 10 pts · 4h
Gives you (up to) 52 shots at any plans, perfect
adarza@lemmy.ca · 1 pts · 2h
%j/%Y
even simpler, it's all numbers.
chickenf622@sh.itjust.works · 11 pts · 4h
ISO 8601RFC 3339 (yyyy-mm-dd) for storing dates in software. Any format that that goes in the order of day, month, and year for conversational/presentational purposes, preferable the format is dynamic depending on the user's locale (even for those that want the month first). There now everyone is happy.Edit: switched to RFC 3339 since it is a subset of ISO 8601 that is more strict, and I love semantics.
dan@upvote.au · 5 pts · 3h
RFC3339 is better than ISO8601 since it doesn't allow some of the esoteric formats, and allows some useful formats that ISO8601 doesn't (like separating date and time by a space instead of by
T)For example,
2026-W32-1is also a valid ISO8601 date: Monday on the 32nd week of 2026. That format isn't allowed with RFC3339.https://ijmacd.github.io/rfc3339-iso8601/
chickenf622@sh.itjust.works · 3 pts · 3h
Damn it I forgot about the duration part of ISO 8601 (which is also super useful and I love it). I'll amend it to RFC 3339 to be more exact in what I mean (even though the specified format should prevent the more esoteric formats).
dlsloop@lemmy.zip · 11 pts · 5h
I'm a YYYY/MM/DD man myself
Bahnd@lemmy.world · 6 pts · 3h
[ISO-8601 MAN SWOOPS IN FROM THE SKY]
You are close, work on your punctuation, see me after class
[Dramatic super hero exit]
dlsloop@lemmy.zip · 2 pts · 3h
Wow, I was really not expecting us to get this far into the weeds in this thread but I suppose I should have lol
drath@lemmy.drath.ru · 8 pts · 1h
Months are stupid anyway, lets drop them and swap for what they were supposed to represent instead: the moon phase, so today would be 216-2026-Waning Gibbous
M137@lemmy.today · 7 pts · 51m
ITT: people saying one thing is better than any other without thinking of context.
If I want to know today's date ISO 8601 isn't a good answer. And if I put stuff in folders by date then DD-MM-YYYY is a real bad way to do it. But MM-DD-YYYY is the worst one no matter the context.
raspberriesareyummy@lemmy.world · 3 pts · 46m
Can be tailed to the relevant bit though.
KernelTale@programming.dev · 1 pts · 6m
I like YYYY-MM-DD because then I don't have to figure out half the time if they used MM-DD-YYYY or if they were sane.
DarrinBrunner@lemmy.world · 6 pts · 4h
April 25th.
We've already established this.
Because it's not too hot and not too cold. All you need is a light jacket.
Dave@lemmy.nz · 1 pts · 31m
I can tell I'm on Lemmy because of how many ISO 8601 comments I had to scroll past to find this comment.
Olmai@lemmy.world · 6 pts · 5h
Im more of a Medjool guy myself. Not sure what everyone else is talking about.
Bishma@discuss.tchncs.de · 6 pts · 3h
53 comments and I'm the first effusive nerd to bring up unix epoch? Nothing happened before 0 (1970-01-01 00:00:00) anyway.
blackbeans@lemmy.zip · 3 pts · 2h
Epoch is signed though, that 1970 date is the midpoint
whotookkarl@lemmy.dbzer0.com · 6 pts · 1h
1785793853 seconds since Linux epoch
OttoVonNoob@lemmy.ca · 5 pts · 4h
Apparently im a freak who is MM/DD/YEAR.
Baizey@feddit.dk · 11 pts · 4h
Also known as an American™️
death_to_carrots@feddit.org · 10 pts · 4h
Yes, you are and you should feel shame about you.
Paradachshund@lemmy.today · 2 pts · 4h
While it's confusing in a vacuum, it's also just the way we say it out loud in american English (April 20, 2026), so it's not that weird when you think about it like that.
blackbeans@lemmy.zip · 4 pts · 1h
However for countries that adopt dd-mm-yyyy, it's also completely natural to say it out loud in that way (20 April 2026). So by that reasoning we will never end up with a universally accepted date format.
Paradachshund@lemmy.today · 2 pts · 59m
Yep, I agree. There's no wrong answer, and language differs by culture.
davidagain@lemmy.world · 1 pts · 22m
There's a right answer, and it's yyyy-mm-dd.
davidagain@lemmy.world · 1 pts · 23m
That's MMM d yyyy, not mm dd yyyy. It removes the ambiguity but also removes the sortability. yyyy-mm-dd for the win.
JackbyDev@programming.dev · 1 pts · 4h
I think it's better than day month year but both are worse than year month day.
hakunawazo@lemmy.world · 5 pts · 4h
https://www.trekterest.com/stardate
henfredemars@infosec.pub · 4 pts · 5h
3 Aug 2026
You can’t guess wrong.
blackbeans@lemmy.zip · 1 pts · 2h
The Spanish would write Ago
The French would write Août
The Greek would write Αυγ
Arabic speaking would write أغسطس
Using words doesn't seem as universal as numbers.
My_IFAKs___gone@lemmy.world · 4 pts · 3h
YYYYYMMDD
I prefer to think we're in the year 12026, since homo sapiens really got things going around 10,000 BCE.
eestileib@sh.itjust.works · 4 pts · 4h
That's a path I can't walk buddy, I think it's better we end it here before we get too attached.
Pudutr0n@lemmy.world · 2 pts · 5h
it's like looking into a mirror
Kolanaki@pawb.social · 2 pts · 4h
February 23.
Because it's muh birfday 😋
TheImpressiveX@lemmy.today · 2 pts · 3h
@RemindMe@mstdn.social pm 2027-02-23
pewpew@feddit.it · 2 pts · 4h
Correct opinion.
brognak@lemmy.dbzer0.com · 1 pts · 6m
DD(First 3 of Month, All Caps)YYYY examples: 01JAN2026, 24MAR1987,20DEC3065
This is how I had to write dates when I worked for a cGMP pharma manufacturing facility and did controlled paperwork. The idea was it was it was impossible for any mistakes when reading the date, only the days were 2 digits, the month was letters, and the year was 4 digits.
Basically all of the validated SOPs were written so that anyone could pick up the paperwork and execute the instructions, and the inverse had to be true as well anyone picking up a completed SOP should be able to read and follow everything written down, and literally every step in the process required initials and date it was executed.
Fun fact, if you fucked up and wrote something wrong or illegibly you were punished twice, once because you had to strike out the mistake, initial date the strikeout and write correctly the next time, and the second was when you get stink eyed by the QA people who have to review all the paperwork before it's scanned and logged back into documentum.
EmpathicVagrant@lemmy.world · 0 pts · 4h
DD MON YEAR is the only one that’s not ambiguous on November tenth and the like. 10 Nov 2022 is less confusing than either 11/10/2022 or 10/11/2022 and is without a doubt never confusing.
davidagain@lemmy.world · 1 pts · 21m
yyyy-mm-dd is an international standard. It's better because it's sortable.