Holy Days of Obligation are special solemnities on which Catholics are called to participate in the celebration of Mass, just as we do each Sunday. The Church sets aside these days so that we may celebrate and enter more deeply into some of the great mysteries of our faith and honor important events in the lives of Jesus, Mary, and the saints. The Catechism teaches that Catholics are bound to participate in Mass on Sundays and other holy days of obligation.
Holy Days of Obligation
Solemnity of Mary, Mother of God – January 1. We begin the new year by honoring Mary under her greatest title: Mother of God.
The Ascension of the Lord – Forty days after Easter. We celebrate Jesus Christ ascending into heaven and returning to the Father.
The Assumption of the Blessed Virgin Mary – August 15. We celebrate the Blessed Virgin Mary being taken body and soul into heavenly glory.
All Saints – November 1. We honor all the saints in heaven, both those known to us and the countless faithful souls whose names are known to God alone.
The Immaculate Conception of the Blessed Virgin Mary – December 8. We celebrate that Mary, from the first moment of her conception, was preserved from original sin by the grace of God.
The Nativity of the Lord – Christmas – December 25. We celebrate the birth of Jesus Christ, our Savior.
What does “obligation” mean?
On Sundays and holy days of obligation, Catholics are called to participate in Mass and to set aside unnecessary activities that interfere with worship, the joy proper to the Lord’s Day, and appropriate rest.
Every Sunday Is a Holy Day
Sunday remains the primary holy day for Christians because it is the day of Christ’s Resurrection. The Sunday Eucharist lies at the heart of Catholic life and worship.
Holy Days Link

