Solemnity of the Immaculate Conception – Monday December 9, 2024
This year, December 8th is the Second Sunday of Advent. As a result, the observance of the Solemnity of the Immaculate Conception of the Blessed Virgin Mary, the Patronal Feast Day of the United States of America, will be transferred to Monday, December 9th.
In previous years when December 8 has fallen on a Sunday it was the practice in the United States to indicate that the obligation to attend Mass does not transfer with the liturgical observance.
Given recent clarifications on this practice from the Dicastery for Legislative Texts and the USCCB Committee on Canonical Affairs and Church Governance, we now know that the feast “must be observed as a day of obligation on the day to which it is transferred.” In light of this information, the Solemnity of the Immaculate Conception on Monday, December 9, 2024, is to be observed as a holy day of obligation, contrary to what was published in the Ordo and USCCB 2025 liturgical calendar before receipt of the clarification.