The pill

So I've been on the pill for nearly a year now, and I know that in order to make birth control pills most effective they have to be taken at the same time every day. But what's considered the same time? Is a 1 hour window before/after your scheduled time acceptable? Or does it seriously have to-be-to-the-minute, same time, every day. 
​I do take it almost exactly the same time daily, but I'm asking out of curiosity. I've heard so many different responses to this question