Non-programmers don't care about this nearly as much as we do. The prevailing attitude is "Ok sure there are edge cases, but so what? My use case is simple".

And after thinking about it a lot more, I think this attitude is actually more sensible than mine used to be. Why do we as programmers keep trying to fit a square peg into a round hole? Timezones are a political construct, not a mathematical one.

We should address edge cases by deferring to people as much as possible. Oh, you find it annoying to enter an offset? Don't worry about it, it's optional! Your dentist will expect you for your cleaning at 8:00am +/- 5 hours.

If we keep smoothing over the rough edges for our users, the problem will only get worse. Better to make timezones as painful as possible for as many users as possible. They'll eventually vote for something less obnoxious.