@z428 @thomas

That standard is way richer than just the date format. I use it not only for computer-related stuff, but also for private purposes, like paper diary/notes, or meeting minutes as it allows to capture intervals, durations or week numbers. Also you can chose between more concise, or more readable forms.

What I wonder about is this: how come somebody “discovers” it only in 2021. Either the person is very young, or was living under a rock for the past 3-4 decades.