Honestly I prefer saying “Good Day” in Czech as well (that’s the most abundant one used here).

At some point I realized that the whole thing has silent “I wish you”, which also means that if I say “Dobrý den” (==“Good day”) I’m actually being more generous. So correcting me to “Dobrý večer” (== “Good evening”) because it’s 7 PM or whatever is actually not just petty but also kind of a dick move.

(Edit: I also realize that my explanation is probably the pinnacle of pettiness, with just a little pinch of dickmoveines on top…)