The Vigil for Christmas, and not the Fourth Sunday of Advent, should be celebrated at evening Masses on December 24 this year. The USCCB’s Secretariat of Divine Worship has noted that, in the opinion of most canonists, each of these days of obligation must be fulfilled with a separate Mass.
December 24 and 25: Fourth Sunday of Advent and Christmas Day
by Fr. Matthew Ernest | Dec 1, 2017