Unimportant sidenote: I don't like the naming of these "falsehoods programmers believe about X" lists. Surely programmers are more likely to be conscious of these not being true than non-programmers.
Unless you work all day on time-related software, you'll probably never encounter most of these quirks.
Humans don't write in BNF. We expect, rightly or wrongly, for other humans to use Postel's law to interpret what we mean.
Computerphile managed a much better title[1]: The Problem with Time & Timezones
A "(for programmers)" could be appended if needed.
But of course what happens is the outliers have to deal with these systems that treat them as bad data possessing impossible properties and then the curse and say hey these stupid programmers don't realize that the world is not just like X1 or Y1, but that us rare instances of X2 and Y2 also exist!
And then an expert with sufficient knowledge about all the outliers compiles a list entitled Falsehoods Programmers believe about {X}.
me: programmers are less likely to believe this stuff than non-programmers
you: no, they are not
me: programmers are conscious that time is more complex than it seems to be, therefore they avoid holding simple beliefs regarding it
Average programmer who hasn't done anything datetime-specific: unlikely.