I got all of my application finished by mid August, including the BGO interview. My teacher recommendations were requested before school was out in June and both submitted the recs the second week in August when they returned to school. The guidance counselor confirmed the activities portion of the application within an hour of my submitting it (it generates the e-mail to that individual when you submit it)
I had all of the Nominating sources packages completed by the start of school. I wanted All Academy associated paperwork submitted prior to the start of my senior year so that I could concentrate on the Civilian College apps in the fall. My SAT scores and ACT scores where good enough from the June testing date after Junior year so I knew I would not be taking either again and then could use the October SAT date to take SATII's. Worked out very well. I also received the LOA the first week of October. Interviewed with all 3 MOC's the first week in November and had appointment in hand the second week of November. Luckily I did not have any medical issues.
I personally think the sooner the better so that you can concentrate on the Civilian apps during the fall. Also, what was stated to us at an USNA recruiting session in my home town was that the earlier the better as it is a rolling admissions.
Great and thanks for the time line, that's the exact time line we're on. If you don't mind me asking, how good were your SAT/ACT scores at the end of Junior year for reference?