Come December 1st, I think there should be Christmas songs... prior, no. Let us have fall, winter is long enough.
In my area, we had one stations turn to all Christmas music early (like right after Thanksgiving). Most of the other stations only do one Christmas song per 4 hour rotation... and increase to maybe 2 or 3 an hour until Christmas Eve Day. Then they will do all Christmas music until 6pm Christmas Day, promptly when all Christmas music off the air. (This is at least true for the company my hubby works for... I don't normally pay attention - this is all from hubby.)