The angel said to them, "Do not be afraid; for behold, I proclaim to you good news of grate joy that will be for all the people. For today in the city of David a savior has been born for you who is Christ and Lord." (Lk 2:10-11)
The Christmas season begins with the Vigil Mass of Christmas Eve on December 24. It concludes with the Feast of the Baptism of the Lord, usually the Sunday after the Epiphany.