Programming time (timestamps, timezones, etc.)
Writing code dealing with time can be quite a pain in the a**.
You rapidly find yourself dealing with a myriad of edge cases and weird stuff that looks normal to us humans but is quite hard to formalize as a predictable system.
So here’s a great piece about the subject with everything you need to know.
https://giphy.com/gifs/warnerarchive-classic-film-warner-archive-l0MYOUI5XfRk4LLWM