If you want to get interviews before Dec1, id say even July and August is a tad late - shoot for may or the first week of june at the very latest. Remember, you might get invited for an interview early, but theres no guarantee that you be able to schedule a pre dec 1 interview. For example, i had my AADSAS submitted June 14th...i got 3 pre dec 1 interviews (temple, UDM, CU). Case and BU invited me in late august/september, but at Case when I called to book an interview they were full until Jan., and BU scheduled me for Feb.
So if u want those decision (hopefully acceptance!) letters in your mailbox on Dec.1, absolutely get your application done ASAP!