One year it did start just before Vets Day and just after Election Day. Used to write for Boston Radio Blog and I believe one column was called After Election Day Comes Christmas
WMJX and WODS used to do battling Christmas formats. Both are now Audacy and 106.7 is a sure bet. I think they stopped doing all-Christmas-11-months-per year on its HD 2 though.
Satellite radio will have multiple Christmas stations.
Note that Christmas, New Years, and cold weather (winter wonderland) songs will be heard but not so much Hannukah or Kwanzaa.
Steve Leveille used to spin Tom Lehrer's Hannukah in Santa Monica, though.
For a year or two WBOQ "North Shore 104.9" did all Christmas for awhile though not now, as WNKC with K Love