[tharkun__]

I do wonder why you care about optionality and priority and what those even mean and how it's better in any way. I don't think it's better at all. It's different.

You remind me of a website I found way back for "learning French as a German". The site was actually pretty decent. But then it started teaching you the numbers and the clock and it started off with how the French way of saying numbers and the time is so much more logical and better than the German way. I closed the site immediately and never opened it again and I did not continue learning French at that time. Stopped right then and there.

Priority and optionality do not help with parsing written dates in an internationalized context. And that is true before computers as well.

2021-02-03 is easy to parse as the 3rd of February 2021 because there's no country on earth that uses this date format to mean the 2nd of March 2021, otherwise it wouldn't help at all.

I'd say that they both depend on context. Let's imagine the two of us are talking about "going camping this month". Year and month are optional. If we're talking about "going camping later this year" the year and day are optional "let's go in February". Let's say we're trying to figure out whether to "still go camping this year or next year". Now day and month are optional.

[filoeleven]

Your last paragraph is a strong argument for the American system of month/day/year. Days lose most of their relevance unless they are in the current month, so month-first is much more logical and better, because it gives the mind the necessary accuracy without the useless precision. And furthermore…

Just kidding. Month-first is as crazy as camping in February. I’m only used to it because I’m American. Getting us to switch to day/month/year seems more confusing than switching to year-month-day, because the latter is different enough to remove all ambiguity when reading. 06/08/2021 could be June 8 or August 6, but 2021-08-06 is clear since (to my knowledge) no one has ever used “year/day/month.”

As you say, this all really applies to full written dates only, since conversation relies much more on context anyway. You are forgiven if you stopped reading this comment before now :)