2180 The precept of the Church specifies the law of the Lord more precisely: “On Sundays and other holy days of obligation the faithful are bound to participate in the Mass.” “The precept of participating in the Mass is satisfied by assistance at a Mass which is celebrated anywhere in a Catholic rite either on the holy day or on the evening of the preceding day.”
- Catechism of the Catholic Church # 2180
The Solemnity of All Saints is a Holy Day of Obligation. The Holy Days of Obligation according to their order in the liturgical year are as follows:
- Solemnity of the Immaculate Conception – December 8
- Solemnity of the Nativity of our Lord (Christmas) – December 25
- Solemnity of the Mother of God – January 1
- Solemnity of the Ascension of the Lord – Thursday following the 6th Sunday of Easter
- Solemnity of the Assumption – August 15
- Solemnity of All Saints – November 1
The Solemnities of the Immaculate Conception and Christmas are obligatory regardless of which days of the week they fall upon.
The other four above listed solemnities (Mother of God, the Ascension, the Assumption, and All Saints) are obligatory unless they fall upon a Saturday or a Monday. In cases in which they do fall on a Saturday or a Monday, attendance at Mass, while not obligatory, is highly recommended and commendable.