yes, YYYY-MM-DD HH:MM:SS is the only proper format.
It is sorted from the greatest unit (year) to the smallest unit (second). If you treat them as text and sort alphabetically they still get sorted from oldest to newest.
Other formats don't sort properly.
writing dd.mm.yyyy is like writing time ss:mm:hh
writing mm/dd/yyyy is like writing time mm/ss/hh
If I really have to put YYYY at the end of the date I use the 'dd-mmm-yyyy' format which excel translates based on client locale:
I agree with everything you are saying about sorting and I frequently use YYYY-MM-DD, however I do want to make one point: DD.MM.YYYY does make some human sense as a date format since the year is very rarely important (and if the year is actually important often the day is so unimportant that it can be left out), the month is sometimes important and the day is often the most relevant piece of information.
So for any kind of practical planning that day first order makes some sense, but I wouldn’t die on a hill for it.
Yes! It's not the first time I posted a rant on the net and found myself guilty of the sin the very next day. This time, a web app of mine has big tables full of dates, and I didn't quickly figure out a way to show the full date without too much clutter. So, I used "dd.mm" and postponed a finer design till next year. Guess what, this UI element hasn't changed in the next three years and today I finally stumbled on a bunch of records which really can't be deduced from context.
I agree with and independently also use the parent's modification to ISO8601 with that respect; though I do frequently call the format string that contains whatever magic cookies get that output something similar to iso8601mod. (The modifications: Emit a string rather than a T, and (if included) use the email like +/-OFFSET to indicate the current timezone offset rather than specify a timezone. No offset implies UTC for system times and local time for human-facing times.)
I would argue that its use goes beyond sorting and includes people making mental estimates about time intervals. Having some sort of sensible order helps here, which I'm guessing is YMD for left to right languages and DMY for right to left languages, since that puts the most significant digits first.
It is sorted from the greatest unit (year) to the smallest unit (second). If you treat them as text and sort alphabetically they still get sorted from oldest to newest.
Other formats don't sort properly.
writing dd.mm.yyyy is like writing time ss:mm:hh
writing mm/dd/yyyy is like writing time mm/ss/hh
If I really have to put YYYY at the end of the date I use the 'dd-mmm-yyyy' format which excel translates based on client locale:
- 13-mar-2020 in enUS
- 13-bře-2020 in czech