I was going to use priceline, but they dont let you specify an approx. time when the flight departs. For example, at Pitt I have an interview for 10/1 and 10/2 (2 days required for MD/PhD). So I was going to schedule a return flight for 10/2. However, I have some interviews on that day so I need to be able to specify an approximate time when I can leave (i.e. after 6 PM). I'd rather not schedule the departure for 10/3 because that would mean I would miss an entire day of class, which would be unnecessary and penalize me for attendance. Do any of these online places let me specify an approximate departure time (or place restrictions on times) or do I have to go directly to the airline websites?