Quote Originally Posted by Полуношник View Post
Мама спросила сына, знает ли он, когда открыт магазин.

The present tense.

Доктор спросил, болит ли голова.
Я спросил Мишу, было ли трудно... (because asked / had been)
You really found something to cavil at I don't really see any difference between

Доктор спросил, болит ли голова and Доктор спросил, болела ли голова.

Well, maybe there might be a subtle difference in some isolated contexts but that is obviously irrelevant