In U.S. popular culture, the Christmas season starts the day after Thanksgiving and ends the day after Christmas. In the traditional liturgical calendar of the Catholic Church, the four weeks prior to Christmas are not the Christmas season, they are Advent, a penitential, preparatory season. Christmas season begins on Christmas and lasts 12 days (yes, those 12 days) until January 6, which is Epiphany, and starts the Epiphany season. So right now, we can still be in the midst of Christmas if we want. In fact, by the old tradition we wouldn't even have brought out our Christmas decorations until Christmas Eve or Day.
I'm not Catholic, but I'm attracted to Catholic traditions. So I searched the web until I found out what other saints and events are celebrated during those 12 days of Christmas. I found a page that told me, and here is some of the knowledge I gained:
1st day: December 25 Christmas
2nd day: December 26 Stephen (when Good King Wenceslas looked out)
3rd day: December 27 John the Evangelist (one of the 12 apostles; wrote the Gospel of John and three epistles)
4th day: December 28 Holy Innocents (the boys 2 and under Herod had killed in Bethlehem)
5th day: December 29 Thomas Becket (Archbishop of Canterbury, killed by knights at the hint of Henry II of England)
6th day: December 30 Our Lady of Bethlehem, Egwin of Worcester
Sunday after Christmas: Holy Family (12/31 if Christmas is on Sunday)
7th day: December 31 Pope Sylvester I
8th day: January 1 Mary Mother of God, Circumcision of Jesus
9th day: January 2 Basil the Great, Gregory of Nazianzen
10th day: January 3 Most Holy Name of Jesus, Genevieve
11th day: January 4 Elizabeth Ann Seton
12th day: January 5 John Neumann
January 6 is Epiphany, the day Christ was first made manifest to the Gentiles, personified by the Wise Men, or Magi. The first Sunday after Epiphany celebrates the baptism of Jesus. Epiphany lasts until Ash Wednesday and the beginning of Lent.
As I write this, it is still only the 5th day of Christmas, so if anyone is feeling a post-Christmas letdown, turn your sparkly lights back on, put Christmas carols back on the CD player, and enjoy another week of Christmas.