Dies Festi de Praecepto
The days, besides every Sunday, on which a Catholic in the United States is bound to hear Mass — for this year and the two that follow.
Every Sunday is a day of obligation. Beyond the Sundays, the Church names certain feasts on which the faithful are likewise bound to take part in the Mass and to rest, as far as they can, from work that keeps them from the worship owed to God (CIC can. 1246–1248). The obligation may be satisfied at any Mass celebrated in a Catholic rite on the day itself or on the evening before.
The dates below are worked out from the law in force in the United States, not copied from a list, so they are right for whichever year you are reading in. The obligation follows your diocese, not the calendar your parish celebrates: the list is the same for the 1962 and the 1969 forms.
Past
Mary, Mother of God
On the 1962 calendar, the Octave Day of the Nativity
Obligatory
Past
The Ascension of the Lord
Obligatory
Thursday in the provinces of Boston, Hartford, New York, Newark, Omaha and Philadelphia. In every other diocese of the United States it is moved to Sunday, 17 May, and the Sunday Mass is the one owed.
Past
The Assumption of the Blessed Virgin Mary
Obligation lifted
Falls on a Saturday this year. In the United States the obligation to attend Mass is lifted when this day falls on a Saturday or a Monday; the feast itself is still kept.
All Saints
On a Sunday
Falls on a Sunday this year, so the Sunday Mass is the one owed.
The Immaculate Conception of the Blessed Virgin Mary
Obligatory
The patronal feast of the United States.
The Nativity of the Lord (Christmas)
Obligatory
Mary, Mother of God
On the 1962 calendar, the Octave Day of the Nativity
Obligatory
The Ascension of the Lord
Obligatory
Thursday in the provinces of Boston, Hartford, New York, Newark, Omaha and Philadelphia. In every other diocese of the United States it is moved to Sunday, 9 May, and the Sunday Mass is the one owed.
The Assumption of the Blessed Virgin Mary
On a Sunday
Falls on a Sunday this year, so the Sunday Mass is the one owed.
All Saints
Obligation lifted
Falls on a Monday this year. In the United States the obligation to attend Mass is lifted when this day falls on a Saturday or a Monday; the feast itself is still kept.
The Immaculate Conception of the Blessed Virgin Mary
Obligatory
The patronal feast of the United States.
The Nativity of the Lord (Christmas)
Obligatory
Christmas binds on any day. With the Sunday after it, that is two obligations, and one Mass does not satisfy both.
Mary, Mother of God
On the 1962 calendar, the Octave Day of the Nativity
Obligation lifted
Falls on a Saturday this year. In the United States the obligation to attend Mass is lifted when this day falls on a Saturday or a Monday; the feast itself is still kept.
The Ascension of the Lord
Obligatory
Thursday in the provinces of Boston, Hartford, New York, Newark, Omaha and Philadelphia. In every other diocese of the United States it is moved to Sunday, 28 May, and the Sunday Mass is the one owed.
The Assumption of the Blessed Virgin Mary
Obligatory
All Saints
Obligatory
The Immaculate Conception of the Blessed Virgin Mary
Obligatory
The patronal feast of the United States.
The Nativity of the Lord (Christmas)
Obligatory
Christmas binds on any day. With the Sunday before it, that is two obligations, and one Mass does not satisfy both.
Where a bishop dispenses from an obligation in his own diocese — for weather, or for a grave local reason — his decision governs. When in doubt, ask your parish.
Sources
Code of Canon Law, can. 1246–1248.
United States Conference of Catholic Bishops, general decree on holy days of obligation (1991, confirmed 1992).
Related Reading
The Sacred Calendar — every feast, season and colour of the year.
The Precepts of the Church — the first of which is Mass on Sundays and holy days.