Saturday, Jan. 1, 2011, marks the solemnity of Mary, Mother of God, which in 2011 is not a holy day of obligation because it falls on a Saturday. The solemnity of the Epiphany of the Lord follows on Sunday, Jan. 2. Although both are ranked at No. 3 in the Table of Liturgical Days, as a solemnity of the Lord, the Epiphany outranks the solemnity of Mary, Mother of God. Just as the Mother of God points the way and leads us to her Son, her solemnity gives way to the Epiphany. Therefore, Mass on the evening of Jan. 1 is the vigil of the Epiphany, and Evening Prayer I of the Epiphany is prayed.
— Archdiocese of St. Paul and Minneapolis