It used to be a novelty...

...when a radio station started playing continuous Christmas music before the day after Thanksgiving.  In 1983, KCFM 97.1 FM ran newspaper ads promoting its 25 days of Christmas music, running December 1-25.  At the time, it was highly unusual for a radio station to attempt this.  Since at least 2001, in order to boost ratings, it has been common for stations on the cusp of a format change to play continuous Christmas music.  In some instances, it even starts before Halloween.  Admittedly, Nat King Cole's version of "The Christmas Song" is stirring, and Bing Crosby's take on "White Christmas" has held up through the decades; still, Christmas music prior to Halloween is rushing things.