I want to ask the teacher _____ we will take a day off.答案是填when,为_英语解答

I want to ask the teacher _____ we will take a day off.答案是填when,为什么不用where?

人气：338 ℃　时间：2020-03-18 14:47:43

解答

这句话的意思应该是我想问老师我们什么时候可以休一天假!
如果用where那怎么理解?