Holy Days of Obligation The Archdiocese of Los Angeles usually observes 4 solemnities designated as Holy Days of Obligation with the obligation to participate in Mass: Christmas (December 25), Mary, Assumption (August 15), All Saints (November 1) and the Immaculate Conception (December 8).The Ascension of the Lord is celebrated on the Seventh Sunday of Easter. In the dioceses of the California province (including the Archdiocese of Los Angeles), the Solemnity of Mary, Mother of God (January 1) is not celebrated as a holy day of obligation. The U.S. Conference of Catholic Bishops’ Committee on the Liturgy has provided the following guidelines for determining exceptions to the above observations:
- when January 1, August 15, November 1 fall on a Saturday or a Monday, the obligation to participate in Mass does not hold.
- when December 8 falls on a Saturday or a Monday, the obligation to participate in Mass remains.
- when December 8 falls on a Sunday, the observance is transferred to Monday, December 9 and there is no obligation to participate in Mass.
