Minor controversy which I hope can be easily solved. Cadets must have 8 weeks between promotions, but can a review board be scheduled before the 8 week period is up.
If the Cadet has completed all of the requirements, I would have no problem holding a review board at week 7 with the promotion occuring the folowing week (provided the Cadet doesn't do something really dumb in between).
I will give you my opinion since there's no real guidance (that I'm aware of) in this area...
You should only schedule a review board once a cadet completes all of his or her promotion requirements (tests, character development, SDA, etc.). If this happens before the eight weeks are up, great; everything is done and you just have to wait for the clock to run out. If the cadet finishes super early (before week six), I'd schedule the review board for week seven to ensure the maximum amount of time to evaluate the cadet's readiness for promotion.
The way you plan your meetings really helps in resolving this dilemma. For example, putting your testing/PT nights as far from the promotion night as possible gives time in between to do board of review.
EXAMPLE:
Week 1: Testing/PT
Week 2: Boards of Review
Week 3: Boards of Review
Week 4: Promotions
Of course, the other promotion requirements fall in there, but it gives you plenty of time to see who's eligible. I see no issue in providing a review board before the cadet is technically eligible (say they don't have the Character Development lesson, but there is one coming up the following week), as long as they are 100% good to go by promotion night.
Review Boards are technically optional, but you must give feedback (on a CAPF 50) at least once per phase. So, you can really do them whenever you'd like. Most squadrons like to incorporate them into their normal promotion routine.