From time to time, the liturgical laws governing the Church’s calendar give rise to consecutive solemnities, or high feast days that follow in successive days. Given that the celebration of a solemnity begins on the preceding evening, questions often arise concerning which Mass texts and readings should be used on the evening when the consecutive solemnities overlap. For example, in 2023, the Fourth Sunday of Advent will be celebrated on December 24, and the Nativity of the Lord (Christmas) falls on the very next day. Catholics may wonder which celebration they will encounter if they attend Mass on the evening of December 24: the Fourth Sunday of Advent or Christmas Eve? 

These types of questions may be answered by consulting the Church’s Table of Liturgical Days and giving precedence to the higher-ranking day. For example, in the case of the Fourth Sunday of Advent and Christmas in 2023, both are days of precept [obligation], but Christmas occupies a higher place on the Table of Liturgical Days. Therefore, at Masses scheduled on the evening of Sunday, December 24, the Vigil Mass for the Nativity should be celebrated.

In these types of situations, pastors will also frequently receive questions concerning the fulfillment of the obligation to attend Mass. In the opinion of most canonists, the obligation for each solemnity (in this case, one for the Fourth Sunday of Advent and another for Christmas) must be fulfilled with a separate Mass. The fulfillment of the Mass obligation does not depend on which Mass prayers and readings are used in the celebration, but rather, on the time of day at which one attends Mass. For example, the obligation for the Fourth Sunday of Advent may be fulfilled at any Mass from the evening of Saturday, December 23 and throughout the entire day of Sunday, December 24. That is, one may attend the anticipated Mass for the Fourth Sunday of Advent, or any Mass (even a Vigil Mass for Christmas) on that Sunday in order to fulfill the first Mass obligation of the weekend. The second obligation (for Christmas) may be fulfilled from the evening (after 4pm) of Sunday, December 24 and throughout Monday, December 25.

Fourth Sunday of AdventNativity of the Lord (Christmas)
Obligation may be fulfilled from the evening (after 4pm) of Saturday, December 23 and throughout Sunday, December 24Obligation may be fulfilled from the evening (after 4pm) of Sunday, December 24 and throughout Monday, December 25
Obligation may be fulfilled at:

• Anticipated (Saturday evening) Mass or Mass of the Fourth Sunday of Advent

• A Vigil Mass for Christmas on December 24

Obligation may be fulfilled at:

• Any evening Mass (after 4pm) on December 24

• Any Mass on December 25

This admittedly complex arrangement should be taken into consideration by parishes when planning a holiday weekend Mass schedule that will accommodate the fulfillment of both Mass obligations. It is also worth noting that canon 1245 and archdiocesan particular law allows for pastors and incardinated priests to “grant in individual cases [but not for an entire parish or larger group] a dispensation from the obligation of observing [this precept].” As well, while the need to fulfill both obligations is a prevailing canonical opinion, confessors should take into account the existence of a canonical doubt on this issue when attending to this matter in the confessional.

In arranging priest coverage for the Mass schedule during this weekend, pastors will want to keep in mind the canonical rule (canon 905) that priests ordinarily are permitted to celebrate the Eucharist only once a day, but have been given permission to celebrate Mass twice on weekdays and three times on Sundays and Holy Days of obligation for the sake of pastoral need. As such, in 2023, a priest may celebrate up to three Masses on both December 24 and December 25, respectively. 

One last consideration concerns the timing of a Vigil Mass for Christmas. As described above, the Code of Canon Law permits the fulfillment of a Mass obligation on the evening of the preceding day (canon 1248). As to what constitutes “evening,” the Code does not establish a definitive time. The most recent statement by the Holy See on this question is Pope Pius XII’s apostolic constitution Christus Dominus (1953), which set the hour of 4pm as the earliest time for anticipated and vigil masses. Some readers may recall that, during the COVID-19 pandemic, a special concession was made to allow for Christmas Masses to be scheduled earlier than 4pm so that churches would not be overly crowded and to allow for the practice of “social distancing.” This permission has not been renewed in the intervening years, and so, the earliest start time for a Vigil Mass for Christmas in 2023 is 4pm.