Some years ago in a chain of discussion the more typical simple pyramid representation of date formats was improved to incorporate every (big and) little detail of the various formats accurately.
The annotated regions of usage are debated however.
The first insight is that numbers themselves are ordered most to least significant, that's why every numeric element is sloped top to bottom. This shows why dd.mm.yyyy is not well-ordered, even ignoring the time component.
Then, am/pm is actually its own segment of the time notation when it is used, and as the biggest is misplaced when put after time.
Put between date and time it is still inefficient, but at least placed in order (and is alphabetically sorted).
Another neat detail is the quirk of 12h time to call the first hour 12 instead of 00. This is represented by the lowest section of the hour bar spiking to be the widest.
One remaining inaccuracy is that the width of the bars does not match their encoded amount of information. It would be sensible to have the day be 5x wider than am/pm, and the (4 digit) years 2.6x as wide as the days, but alas that would be too impractical for such a well-designed infographic.
I inverted the original because I prefer darkmode. Here is the original
!rfc3339@programming.dev
How can YYYY-MM-DD be proprietary? Am I supposed to be paying someone every time I write the date or something?
You know YYYY-MM-DD, but there could be edge cases you don't know off the top of your head (leap days, time zones, daylight savings, etc) that you might have to look up.
Theoretically, if you were a programmer working to implement it in your organization's code, and you had to look up the standard, it would be behind a paywall. Organizations often have subscriptions like for journal papers.
Good thing is that iso8601 is so monstrously complex with so many obscure formats you probably don't want anyway, that you're better off following another standard.
HTML has a set of allowed formats for example that includes parts of rfc3339 and of iso8601, but also stuff like the 'most basic' "yyyy-mm-dd hh:mm:ss", which is neither in rfc (which requires a trailing Z) nor in iso (which needs the T).