The Solemnity of the Immaculate Conception of the Blessed Virgin Mary, Patroness of the United States, is always a holy day of obligation. A vigil Mass for the immaculate Conception may be celebrated on Friday, December 7th after 4:00pm. All Masses before 4:00pm on Saturday, December 8th celebrate the Immaculate Conception. Masses after 4:00pm on Saturday, December 8th anticipate the Second Sunday of Advent.