Last year, most interviews start around late Sep. and early Oct. But they usually send u the interview offer at least few weeks before the interview date. Here are the few schools I remembered:
Case: their interview process begin really early, around mid-Aug.
NYU: relatively early, mid Sep.
Stony Brook: End Sep.
Michigan: Early Oct.
UNLV: early Oct.
USC: early Oct.
Temple: early Oct.