- Must be an expert in strftime / Date / datetime
This is something everyone expects devs should know, but unfortunately working with timezones and date objects is super hard.
The example with %G is too specific for the whole problem. There are always date conversion / libraries / ISO / Locale specific / etc.. Damn it, even Apple returns specifically "PST" in their own responses ( why?! ) [1].
Everyone has a story with manipulating date / time and that's already a sign how bad the situation is.
Trying to be positive ( and funny ), I hope there will be some big and great conference in around 1747247444 [2], where the United Nations' computer department decides that it's too stupid to have so many rules for measuring time and sets a unified standard with no DST, leap years, etc.