Is this a bad time to mention 夕食 (ゆうしょく) and some of the many other similar words used to mean "evening meal" too? :D
I don't think there really is any difference between the two you mentioned either; I think they're used for exactly the same meaning/politeness/formality. 夕 and 晩 both essentially mean "evening". However, to be a little more specific, I think 夕 specifically refers to sunset and the time around when it is occurring, while 晩 simply refers to the evening (the counterpart to 朝 "morning").
I'm fairly certain the same time of day is understood whichever one people say, but I don't really know at all. Apparently there's the term 夜ご飯 (よるごはん) also meaning "evening meal". 夜 itself is more specifically night (夜間 "nighttime" being the opposite of 昼間 "daytime"). So I think 夜ご飯 is what is used by people who eat dinner later towards or at nighttime.
January 2, 2016 at 10:16pm