As the song reminds us, there are twelve days of Christmas, December 25 through January 5. The Epiphany of our Lord, which begins the season of Epiphany, is always January 6. Therefore, during January we will finish up the Christmas season, and begin the Season of Epiphany.
The season of Epiphany focuses on the revelation of who Jesus is. The season of Epiphany lasts through February, and then culminates with Transfiguration Sunday the first Sunday of March.