Although in the minds of many the Christmas season begins when Halloween ends, Christmas does not begin until December 25th. Furthermore, Christmas is not restricted to December 25. Christmas is actually a season in the Church Year that lasts for twelve days. It last from December 25 until the Baptism of our Lord, which is always the Sunday after January 6 . Sometimes Christians use the term “Christmas” to refer to December 25, and Christmastide to refer to the season of days after December 25.
MEANING: The Incarnation and birth of Christ
Christmas is the feast of the Incarnation and celebrates the enteringof the eternally existent second Person of Holy Trinity into the world. It was not just a matter of God appearing in human form, it was about the Eternal Son taking on human nature and a human body, so that as the Nicene Creed says the one was “true God from true God. . . .became incarnate from the Virgin Mary and was made man.” Although the birth of Christ is celebrated and acknowledged, December 25 is not Jesus’ birthday. Rather, it is a day on which we celebrate the Incarnation, which God accomplished by means of a birth.
ORIGIN: 4th century
It appears that some Christian communities began celebrating this holy day as early as the fourth century, perhaps in North Africa, and that it was common throughout the Universal Church by the fifth century.