Is Dec. 9 a holy day of obligation this year?

Q: Is Dec. 9 a day of obligation? Is this rule new? Is it just for America? (Rochester, New York)
A: Normally Dec. 9 is not a holy day of obligation, but it is this year in the United States due to a quirk of the calendar.

For some background, Canon 1246 of the Code of Canon Law tells us that "the Lord's Day, on which the paschal mystery is celebrated, is by apostolic tradition to be observed in the universal Church as the primary holy day of obligation" -- that is, a day where the faithful are obligated to attend Mass. "In the same way, the following holy days are to be observed: the Nativity of Our Lord Jesus Christ, the Epiphany, the Ascension of Christ, the feast of the Body and Blood of Christ, the feast of Mary the Mother of God, her Immaculate Conception, her Assumption, the feast of St Joseph, the feast of the Apostles Sts. Peter and Paul, and the feast of All Saints."

But the same canon goes on to add: "However, the Episcopal Conference may, with the prior approval of the Apostolic See, suppress certain holy days of obligation."
This means that the actual holy days of obligation a Catholic is required to observe depends on, essentially, where they live, since the local bishops' conference is empowered to edit the universal list of obligations to better account for the pastoral needs of the people in their region.

The U.S. Conference of Catholic Bishops' "complementary norms" (i.e., the list of church laws specific to the United States which the Code of Canon Law empowers bishops' conferences to make) tells us that that American Catholics, in a departure from the universal law, are not obligated to observe the feasts of St. Joseph or Sts. Peter and Paul as holy days of obligation.

Where things can get a little bit confusing is how the USCCB complementary norms also indicate: "Whenever January 1, the solemnity of Mary, Mother of God, or August 15, the solemnity of the Assumption, or November 1, the solemnity of All Saints, falls on a Saturday or on a Monday, the precept to attend Mass is abrogated."

This means that for these specific feast days, if and only if they fall on a Saturday or Monday in a given year, then the faithful already fulfill their obligation by attending Mass as usual on the neighboring Sunday.

Note that the solemnity of the Immaculate Conception, as the patronal feast of the United States, is not included in this list of "holy days of occasional non-obligation." Even if the Immaculate Conception falls on a Saturday or Monday, the faithful of the United States are obliged to attend Mass that day even if they have already gone to Sunday Mass the day before or after.

The solemnity of the Immaculate Conception is generally not considered a "movable feast." I.e., in contrast to a holy day like Easter where the actual calendar date changes from year to year, the Immaculate Conception is tied to the specific date of December 8.

But this year, Dec. 8 falls on the second Sunday of Advent. Since the Sundays during special seasons such as Advent and Lent have a particular importance in our liturgical year, they take precedence over other feast days. The solution for competing solemnities is to transfer the liturgical celebration of the non-Sunday holy day to the first subsequent available date. Thus, in the year 2024, the solemnity of the Immaculate Conception is celebrated in our liturgy on Monday, Dec. 9.

There was some question among canon lawyers as to whether the obligation to attend Mass transferred along with the liturgical observance of the holy day, but the Holy See in Rome recently clarified that it indeed does. However, because there is still some widespread misunderstanding on this point, some dioceses in the United States are dispensing their faithful from the obligation.