Greetings and farewells

[Aparecium]

Good morning, good afternoon and good evening are greetings.

Goodbye and good night are farewells.

Aren't they?

Yeap

I would say that goodbye and good night can only be used as farewells but that good morning, good afternoon and good evening can be used as farewells or as greetings.

Using those three as farewells is very rare these days though, I suspect. They seem overly formal.

Agreed.