I don't understand the difference between the english "what month are we in" and "what month are we on". I feel like as a native english speaker the fact that I don't know should hold some weight, but if there is some subtle difference between those two english sentences that a pedant might now better than myself, I would like to understand.
Native english speaker here as well, and I can honestly say I've never heard "what month are we on?" Are you British, American, etc...? The only time I could imagine "what month are we on" is in regards to looking at a schedule, or future event and checking what month is being discussed.
Well, dans and en are both used with time words and phrases ("En avril" or "Dans les mois à venir"), so I think that's what lluqmana is wondering about here. I'm going to guess no because "en" seems to be reserved for specific named months and "dans" seems to be called for if the noun is modified like this one.