try to send it as soon as possible. if you send your things in the fall, you'll still have a chance, but just not as good of a chance as what you would've had in the summer. schools from what i've seen are pretty good at keeping up with rolling admissions. I remember, by december/january, many schools were already close to accepting their full capacities. In addition, aadsas is notoriously slow which you must consider in your submission deadline.