It's funny you should say this. Reading this article prompted me to future-proof a program I maintain for fun that deals with time; it had one use of utcnow, w

It's funny you should say this. Reading this article prompted me to future-proof a program I maintain for fun that deals with time; it had one use of utcnow, which I fixed. And then I tripped over a runtime type problem in an unrelated area of the code, despite the code being green under "mypy --strict". (and "100% coverage" from tests, except this particular exception only occured in a "# pragma: no-cover" codepath so it wasn't actually covered) It turns out that because of some core decisions about how datetime objects work, `datetime.date.today() < datetime.datetime.now()` type-checks but gives a TypeError at runtime. Oops. (cause discussed at length in https://github.com/python/mypy/issues/9015 https://github.com/python/mypy/issues/9015 but without action for 3 years) One solution is apparently to use `datetype` for type annotations (while continuing to use `datetime` objects at runtime): https://github.com/glyph/DateType https://github.com/glyph/DateType