Throbert McGee
I must insist on reverse translation of "When DID the store open?" then. Because I have doubt, that "когда открыт магазин?" means for you the same as for me.
For me it asks for working hours, and the answer could be: "с 8 до 20 часов, воскресенье- выходной"

она спросила его, знает ли он, когда магазин открывается. This one I like.