The traditional end of the season of Christmas finds the church, by tradition, remembering Matthew’s story of the visit of the wise men. In the larger church around the world, historically, this Sunday has been called Epiphany Sunday. The appearance of the wise men heralds the truth that the good news of Jesus is not just for Israel, but for those from every end of the earth. Epiphany is always January 6th — 12 days after Christmas. (Thus the Christmas carol, The Twelve Days of Christmas.) The church observes it on the Sunday closest to that. This year, that Sunday is January 1 — the first Sunday of the New Year.
The season of Epiphany in the church, which lifts up the revealing of the truth of Jesus to the entire world, runs until Ash Wednesday. In 2017 Ash Wednesday falls on March 1.