According to the Catechism of the Catholic Church,
“The Sunday Eucharist is the foundation and confirmation of all Christian practice. For this reason, the faithful are obliged to participate in the Eucharist on days of Obligation unless excused for a serious reason(for example, illness, the care of infants) or dispensed by their own pastor. Those who deliberately fail in this obligation commit a grave sin.” (CCC 2182)
Purposely missing Mass on a Holy Day of Obligation, just like Sundays, is considered a mortal sin.
“For a sin to be mortal, three conditions must together be met: “Mortal sin is sin whose object is grave matter and which is also committed with full knowledge and deliberate consent.” (CCC 1857).
To ensure you get to Mass and fulfill the obligation, here are the Holy Obligation days in 2025:
1) Wednesday, January 1, 2025 - Solemnity of Mary, the Holy Mother of God
2) Thursday, May 29, 2025 - Solemnity of the Ascension of the Lord (Thursday of the Sixth Week of Easter)
3) Friday, August 15, 2025 - Solemnity of the Assumption of the Blessed Virgin Mary
4) Monday, December 8, 2025 - Solemnity of the Immaculate Conception of the Blessed Virgin Mary Patronal Feast of the United States of America
5) Thursday, December 25, 2025 - Solemnity of the Nativity of the Lord (Christmas)
Important Notes Regarding Holy Days of Obligations in 2025
Vigil Masses cannot be celebrated before 4:00 p.m.
Saturday, November 1, 2025 - the Solemnity of All Saints - is not a Holy Day of Obligation in 2025.
According to the USCCB,
“In accord with the complimentary norm to canon 1246 §2 confirmed for the dioceses of the United States of America, because it is a Saturday, this year the obligation to attend Mass on this date is abrogated.”
Palm Sunday, Easter Sunday, and the Solemnity of Corpus Christi falls on Sundays, already making them obligatory.