On holy days of obligation, Catholics are obliged to participate in Mass. Every Sunday is a holy day of obligation, as are six other days throughout the year. In the United States, these holy days of obligation are

• January 1: The Feast of Mary, the Mother of God
• 40 days after Easter Sunday: Ascension Thursday
• August 15: Assumption of Mary into heaven
• November 1: All Saints’ Day
• December 8: The Feast of the Immaculate Conception
• December 25: Christmas, the Nativity of Our Lord

Remember
Holy days are like Sundays in that Catholics must attend Mass, and if possible, refrain from unnecessary servile work. Some Catholic countries, such as Italy, Spain, and Ireland, give legal holiday status to some of these holy days, so people can attend Mass and be with family instead of at work.

In the United States, Christmas Day (December 25) and the Immaculate Conception (December 8) are always days of obligation. Christmas and Easter (which always falls on Sunday) are the highest-ranking holy days, and the Immaculate Conception is the feast for the United States. However, if any of the other holy days falls on a Saturday or Monday, they aren’t considered holy days of obligation, because they’re back-to-back with Sunday. The concern is that it would be burdensome to many Catholics to have to go to church two days in a row.

To make things even more confusing, some parts of the United States have moved holy days, such as the Ascension from Thursday to the closest Sunday. If in doubt, it’s best to call the local Catholic parish or just go to Mass anyway. Attending Mass is never a waste of time, even if it ends up not being a holy day of obligation.

Europe has four more holy days than the United States observes: January 6 (Epiphany), March 19 (St. Joseph), Corpus Christi (Thursday after Trinity Sunday, which is the Sunday after Pentecost, which is 50 days after Easter), and the Solemnity of St. Peter and St. Paul (June 29).