If there's an event yet to come and two people talking to each other about it, if one of them doesn't know about the day and the time, can he ask (What day is it?) and (What time is it?)? Isn't it misundrestood that he is asking about the day and the time of now?
Example
A: There's a game this month.
B: What time is it?
A: It's at 8:30 P.M.
B: What day is it?
A: On the fifth.