Time zones are complicated, but they are a fact of engineering life. Time zones have [skipped entire days](http://www.bbc.com/news/world-asia-16…) and repeated others. There are time zones that switch to [DST twice per year](https://www.timeanddate.com/time/zone…). But not necessarily every year. In Python it’s even possible to create datetimes with non-transitive equality (`a == b`, `b == c`, `a != c`). In this talk you’ll learn about Python’s time zone model and …