[xmddmx]

Here's my favorite UI/UX bug which has been there for years:

In Calendar (macOS) create a new event.

In the start or end time, type in the Minutes field, but type slowly.

For example, type "2" pause a bit, then type "1"

If there's more than ~300msec pause between the two keypresses, the 2 changes into "02" and then the 1 overrides it, so you end up with "01" instead of 21.

Works with any two kepresses. Same problem in the date fields.

Completely wrong, and super bad for accessibility.