are also pronouns, nouns and conjunctions as well. Why
can be a noun as well as a conjunction. It all depends on how you use them and what you're intended meaning is. As such, the examples you've provided are ambiguous because you could be referring to actions, e.g. when
in regard to the action of something occuring at some time, which would be an adverbial use. Or, you could be saying "what" or "which" time, which would be an adjectival use. Or, you could be refering to the time or date, which would be a nounal use.