Ok, I’ll start with this one since it’s at the top of my bookmark list as it has a time-based reminder embedded.
Daylight Savings Time Rules
I bookmarked it because I made it clear to myself once so I wouldn’t have to remember - and I don’t, without checking this post. 
/edit
BTW, @QiS in the topic was a Wyze staff member (not noted on their profile at present) so it’s an informed discussion…