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
The way I look at it, if I were looking for a date in a calendar, I’m not going to start with the day, find the day and look for the right month, then look for the correct year. I’ll start with the year I’m looking for, go to the correct month, then finally locate the day in question.
In most cases in everyday life the year and month will be the the same as the current ones so the correct year and month wil already be open on most calenders. So looking for the day first does make sense as well.
But you would never look for the day, then flip to a different month while keeping the same day. And if you’re already on the right month, you have completed the step of finding it, because you can verify it’s already open before finding the right day. YMD is the correct search order.