Jean-Baptiste-Camille Corot. The Baptism of Christ. 1844-45
Today the Church celebrates the Solemnity of the Baptism of Our Lord. This brings to an end the season of Christmas. The Church recalls Our Lord's second manifestation or epiphany which occurred on the occasion of His baptism in the Jordan. Jesus descended into the River to sanctify its waters and to give them the power to beget sons of God. The event takes on the importance of a second creation in which the entire Trinity intervenes.
Surprise again! This feast is usually on the Sunday after January 6. In the United States, when Epiphany falls on the same Sunday, the Baptism of the Lord is celebrated on the following day (Monday). So here we are, with a major feast day on a Monday.
Read more about this feast day at Catholic Culture.