Quando is the question word used to ask time. For example:
-Quando sei tornata? (What time did you get back?)
However, if we need to ask the specific time, we use che instead:
-Che ore sono? (What time is it?)
An alternative is che ora è, which is appropriate when it is a singular hour, such as one o'clock (l'una), midnight (mezzanotte) and noon (mezzogiorno).