Funny I recently had someone ask the same thing. This is pretty much the only route you can go. And 🏴☠️ sadly the only reliable one (if the software is popular enough)
Why no real db? Those other 2 features make sense, but if the only option you can use sacrifices the 3rd option then it seems like a win. Postgres is awesome and easy to backup, just a single command can backup the whole thing to a file making it easy to restore.
Find some nerds who live near you, I guarantee they know the best place, we can’t answer your question as it highly depends on which country you live. Not saying you should tell us either.
Honestly the first one is the only one that works when people define the first day of the week differently. On the other hand, it does make you wonder. If Sunday is the first day of the week (as it is in many places) then how is it also part of the weekend?