You can't escape them. There are 12 Days of Christmas contests on the radio, 12 Days of Christmas sales at the mall, 12 Days of Christmas charity drives, and, of course, that very long song.
Most people (in America, at least) seem to assume that these infamous 12 days describe those leading up to Christmas Day, as evidenced by the aforementioned contests and sales.
And yet it is actually that very factor–the American marketing machine–that has led to this erroneous labeling of December 14-25 as The 12 Days of Christmas. For retail business, December 25 marks the end of the Christmas season.
However, in the Christian tradition. The 12 Days actually refer to the celebration of Christ's nativity–also called "Christmastide"–between Christmas (December 25) and Epiphany (January 6), the day that celebrates the visit of the Magi. For this reason, the evening of January 5 is called "12th Night," made famous by William Shakespeare's play of that title.
The days preceding Christmas—four weeks to be exact—are more traditionally referred to as Advent, the time in which Christians anticipate both the First and Second Comings of Jesus to earth. In the historic tradition, Christians don't actually celebrate (or sing about) Christ's birth until Christmas Eve, and then they continue to sing about and celebrate the Nativity for the 12 Festival Days of the season.
I always find it ironic when I hear Christians in America state with conviction–and a little bit of piety–that they won't be tied down by "Catholic" traditions like the Church Calendar, and yet through their actual practices they prove to be constrained by a liturgical calendar of another sort—The Liturgical Calendar of American Commercialism.
They insist that they won't celebrate Epiphany, the Baptism of Christ, Lent, Palm Sunday, Holy Week, Eastertide, Pentecost, Ascension Day, Trinity Sunday, Advent or the traditional Twelve Days of Christmas.
And yet instead, their churches celebrate New Year's Eve, Valentine's Day, Easter Bunny Day, Mother's Day, Memorial Day, Father's Day, Independence Day, Halloween, Thanksgiving and a Christmas season stretching from Thanksgiving to Christmas Day–days with customs rooted not in biblical events or Christian tradition, but in the tradition of American commercialism.
There is no biblical mandate to celebrate the Church Year, and if someone chooses not to follow the traditional Church Calendar, I will not insist that they must. (I will note, however, that I believe one can hold to a very strict Regulative Principle and still find benefit in using the Protestant Church Year. See my comments about this here, and Kevin Bauder's similar comments here.) It really does not concern me whether a church celebrates Christmas during the days preceding December 25 or the twelve days following.
Yet how Christians do celebrate seasons like Christmas does reveal what most influences them. And as I often tell my students, it is impossible to avoid being influenced by some tradition; the question is, which tradition most influences your church's practice, that of historic Christian churches or that of American commercialism?
Scott Aniol, PhD, is an author, speaker, and teacher of culture, worship, aesthetics, and church ministry philosophy. He is chair of the Worship Ministry Department at Southwestern Baptist Theological Seminary. He founded Religious Affections Ministries and has written several books, the most recent being By the Waters of Babylon: Worship in a Post-Christian Culture. He can be found on Twitter @ScottAniol.