I would have to agree w/ the Jan. date. If nothing else, by the time the sub-I rolls around, you have a better idea where you stand, you'll know how many interviews you'll really want to do and the ones you can afford to cancel. Here's something you can do- schedule many of the interviews that you're iffy about ( your "safety" interviews) around the time of your sub i, and the ones that your really gunning for in late dec/ early Jan after you've had a few under your belt.
This of course depends on where you stand for your particular spec. of choice, you could be at the top or bottom of the proverbial food chain and may want to temper my advice depending on your chances of matching.