It is still the time of Christmas and this ends today with the "Twelfth Day," or, the Feast of the Epiphany of Our Lord. This feast originated early in the East and today is a celebration of both Jesus' birth and baptism. In the West the Gospel is the account of the visit of the Magi. The Baptism of Our Lord comes on the octave of this feast. Traditionally, the Western Church hears the Gospel of the boy Jesus in the Temple on the Sunday in the octave, though now it is common to find the Epiphany celebrated on the closest Sunday. These days of Epiphany are among the richest of the year, a celebration of divine "revelation" or "manifestation" combining the blessed Incarnation with the visit of the Magi, Jesus' boyhood visit to the Temple and later baptism. Epiphany leaves off where the Christ-Mass began.
In terms of origin Epiphany is one of the oldest feasts and, like Christmas, Epiphany replaced a pagan solstice festival. Here Christians come to know Mary's son as the Light in this world.