Bahr?

Can somebody please explain to me how American Airlines can change my ticket time by two hours? What is the point of making a reservation and selecting the times that logically meet my flying needs when they are just going to change my flight? We're talking from 9:15am to 7:15am here. That's not small potatoes when the airport's an hour away and I have to get there an hour-ish before the flight. I am flummoxed. Simply flummoxed.