I think it would be relevant to mention at this point that people do not actually greet each other saying "chào buổi tối, chào buổi sáng" in Vietnam! It's weird.
And neither do they in English. Good evening means have a good evening, not hello evening. In my opinion, it should be translated to "chúc bạn một buổi tối tốt lành/vui ve."
Last time I picked "evening" from hints I was marked wrong for not using night. So now I use it and marked wrong as I know I cannot rely on hints.
"Buoi toi" used in a previous question re "do the animals sleep at night" but now it means only evening and night is wrong. Inconsistency, is this a new teaching tool
Context is the key.
"Animals sleep at evening" does not make sense.
"Good night" would not be valid either, because in English they say "good night" when going to sleep, but that in Vietnamese would be "ngủ ngon" (literally "sleep deliciously).