The End Of Christmas

"Though with Twelfth Day [January 6] the high festival of Christmas generally ends, later dates have sometimes been assigned as the close of the season. At the old English court, for instance, the merrymaking was sometimes carried on until Candlemas [February 2], while in some English country places it was customary, even in the late nineteenth century, to leave Christmas decorations up, in houses and churches, till that day. The whole time between Christmas and the Presentation in the Temple was thus treated as sacred to the Babyhood of Christ; the withered evergreens would keep alive memories of Christmas joys, even, sometimes, after Septuagesima* had struck the note of penitence."

From Christmas in Ritual and Tradition - Clement A. Miles (1912)

*Septuagesima Sunday is 63 days before Easter Sunday
In some years, it can be as late as February 22.
In 2010: January 31
See generally Wikipedia: Septuagesima
(http://en.wikipedia.org/wiki/Septuagesima),
accessed February 14, 2007)

Notes:

January 1, New Year's Day, has previously been celebrated as the Feast of the Naming and Circumcision of Christ. Since Vatican II, this feast has been celebrated by Roman Catholics as the Solemnity of Mary, Mother of God.  Links open in a new window at an external site.

January 7, is also Handsel Monday & Plough Monday (always celebrated the first Monday after Epiphany).

January 13. St. Knut's Day. Celebrated in Sweden. According to Miles,

In Sweden Yule is considered to close with the Octave of the Epiphany, January 13, “St. Knut's Day,” the twentieth after Christmas.

“Twentieth day Knut
Driveth Yule out”

sing the old folks as the young people dance in a ring round the festive Yule board, which is afterwards robbed of the viands that remain on it, including the Yule boar. On this day a sort of mimic fight used to take place, the master and servants of the house pretending to drive away the guests with axe, broom, knife, spoon, and other implements. The name, “St. Knut's Day,” is apparently due to the fact that in the laws of Canute the Great (1017-36) it is commanded that there is to be no fasting from Christmas to the Octave of the Epiphany.

See: CHAPTER XVI,"EPIPHANY TO CANDLEMAS," Christmas In Ritual and Tradition by Clement A. Miles (1912).

On February 2 are the celebrations of the Presentation at the Temple, the Purification of the Blessed Virgin Mary, and "Candlemas" — the blessing of the candles to be used during the next year in churches, together with a candle-lit procession, said to be based on Simeon's declaration in the temple when he took Jesus in his arms, and affirmed that he was a light to lighten the gentiles, and the glory of Israel. See generally: Gospel of Luke 2:22-39.

See:

The Every Day Book - William Hone

January 1 - New Year's Day and Hogmany
Handsel Monday (The First Monday After New Year's Day)
Lamb's-wool
January 5 – Eve of Epiphany
January 6 - Epiphany
January 7 - St. Distaff's Day
Plough Monday (The First Monday After Epiphany)
February 2 - Candlemas
Old Shrove-tide Revels
(February 15, with mention of the duties of the king of Christmas)

Brand's

Three Kings Of Cologne
Twelfth Day
New Year's Eve and Day
New Year
New Year's Gifts
New Year's Water
Plough Monday
Hansel Monday and Tuesday
Candlemas Day

The Adoration of the Magi - Gentile Da Fabriano (c. 1370-1427)