Since this is pretty much a normal year, I'd say you're in pretty good shape if all files are complete by mid-September. August MCAT'ers should have their mcat scores be the last thing to complete their file around mid to late October. What you have to remember is that a lot of schools interview applicants by tiers. Not all but many do. Don't be surprised to find your application to be sitting on many hold piles regardless of how early it's complete if you're not numerically qualified for a school.