It isn't "falsehoods all programmers believe..." it's "falsehoods that [some|lots|many|inexperienced] programmers believe..."

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.

But the point is that programmers are less likely to believe these things than ordinary people are.

The point is these are falsehoods whose belief can affect a programmer's work when they get embedded into the systems they create. The point is to correct yourself, not tu quoque your brother.

By putting the intended audience in the title, you grab their attention more.

It's clickbait.

Computerphile managed a much better title[1]: The Problem with Time & Timezones

A "(for programmers)" could be appended if needed.

[1] https://www.youtube.com/watch?v=-5wpm-gesOY

Its not click bait, the contents are what the title claim to be.

But they’re more likely to be impacted.

well basically it's shorthand for "things that do not apply to every locale for X of instance of Y, that programmers have decided to implement as if they do apply to every locale or instance either through not realizing they do not apply or that the non-applicability in some situations are such bizarre outliers in relation to the rest of the world that it has been decided to be an acceptable bug that they will not fix" but that's not very pithy.

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}.

I still encounter forms on the web or input fields in software that prevent me from entering truthful information or that require me to input information that doesn't exist. There are definitely still programmers out there that make assumptions that don't hold in all cases.

No, they are not. Beyond leap years and leap seconds, I know absolutely nothing about time, how to handle all the "daylight savings" and other kind of bullshit. And I actually do not care, at all. Luckily for me, people who do care and know these things have made libraries that can handle it all while expecting only minimal knowledge from me, such as being aware that time zones exist at all.

The reason why you use those libraries is that you know time is difficult and you need to be cautious. You don not blindly believe those statements about time. If pressed to answer whether they are right or wrong you would say that you are not sure.

And I'm not sure how this contradicts what I wrote.

Arguing about this is not productive, so sorry in advance, but just to explain myself:

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

Programmer that have worked with timekeeping: yes.

Average programmer who hasn't done anything datetime-specific: unlikely.