An image of the Immaculate Conception, showing a crowned Mary, was captured in the Chapel of the Choir in St. Peter’s Basilica at the Vatican on May 30, 2023. As Advent approaches, the guidelines for observing the Solemnity of the Immaculate Conception during December 8 and 9, 2024, have been outlined.

The Solemnity of the Immaculate Conception of the Blessed Virgin Mary is a significant Marian feast within the liturgical calendar. This year, December 8 coincides with the Second Sunday of Advent, which takes precedence over other feasts. Therefore, this Marian feast will be observed on Monday, December 9, 2024. The Holy See has confirmed that attending Mass for this occasion is obligatory on December 9. This represents a new interpretation of Church law and establishes that when transferred to December 9, it remains a holy day of obligation.

Bishop Thomas J. Paprocki, Chairman of the USCCB’s Committee on Canonical Affairs and Church Governance, sought clarification from the Holy See regarding obligations when a holy day in Advent falls on a Sunday and is transferred to Monday. In response to his inquiry earlier this year (2024), Bishop Paprocki relayed a memo from October 10 stating: “The feast must be observed as a day of obligation on the day to which it is transferred.”

Consequently, Monday, December 9 will be observed as a holy day of obligation for the Solemnity of the Immaculate Conception.

On December 8—the Second Sunday of Advent—only Masses for this occasion will be celebrated. Attending any Mass from Saturday evening through midnight Sunday fulfills this obligation. However, Masses specifically for the Immaculate Conception are not permitted on December 8.

For those attending Mass from late afternoon on Sunday through midnight Monday fulfill their obligation for both days separately but cannot satisfy two separate obligations with one service.

For further information about Holy Days of Obligation or additional questions related to these observances can be directed to members within church communities or worship offices.