The "music only" channel usually starts playing Christmas music around November 1st, but they don't officially switch to an all-Christmas music lineup until December 1st. However, the stations in my hometown usually start playing Christmas music the day after Thanksgiving, which is the day after Black Friday. They do this so they can start promoting all the great sales and deals for Christmas shopping. So, if you're really eager to hear Christmas music, you could always listen to a station that plays it earlier in the year.