Christmas and the following 12 days ending in the feat of the Epiphany.
The Lectionary readings for Christmas and the following twelve days (culminating in the feast of the Epiphany) invite the church to reflect on the Incarnation (or embodiment) of God as a human being: "The Word became a human being and lived among us, and we have seen his glory...." (John 1:14). In Christ, God enters human history and identifies fully with the human condition.
The traditional colors of the season are White or Gold, symbolizing joy in the light of day.