I personally set a deadline of September 1st, school should have all the application materials including the secondaries(unless it requires an interview to get a secondary application). Some schools begin reviewing applications in august but I think September 1st is a good deadline to set. It would be unwise to cut it close to the school deadline because by then schools will be filled. This means that the AADSAS application should have been submitted by July 1st. That's the timeline that I have operated on, in actuality I sent my AADSAS in on June 15th and got the application processed and sent on July 23rd. This is a good deadline to set.