Principal liturgical feasts
The Church's Holy Days of Obligation are principal liturgical feasts that honor the mysteries of the Lord, the Virgin Mary, and the saints:
Solemnity of Mary, January 1
This feast, closely connected to the feast of Christmas, is the most important and oldest of the major feasts of Mary. Mary's Divine Maternity became a universal feast in 1931. Liturgical reform initiated by Vatican II placed it on January 1 in 1969.
Ascension of Christ, 40 days after Easter
This feast is celebrated the fortieth day after Easter Sunday and /commemorates the elevation of Jesus into heaven by his own power in the presence of his disciples. It is narrated in Mark 16:19, Luke 24:51, and in the first chapter of the Acts of the Apostles.
Assumption of the Blessed Mother, August 15
This is the principal feast of Mary. It has a double purpose: first, the happy departure of Mary from this life and second, the assumption of her body into heaven.
All Saints' Day, November 1
This feast honors all the saints, known and unknown. This feast was first celebrated on May 13, 610, when Pope Boniface IV proclaimed the day Feast of All Holy Martyrs in Rome. The intent was to honor all martyrs who were not included in local records. In 835, Pope Gregory IV changed the date and name to November 1 and Feast of All Saints. A fall date allowed people to celebrate with food from the fall harvest.
Immaculate Conception of Mary, December 8
The Immaculate Conception of Mary, the Mother of Jesus, is the belief that God preserved Mary from any inclination to sin, the inheritance of original sin passed on to all mankind from Adam and Eve. The feast of the Conception of Mary appeared in the Roman calendar in 1476. After the dogmatic definition by Pope Pius IX in 1854, it became the Feast of the Immaculate Conception.
Christmas, December 25
This feast celebrates the birth of Jesus.
Attending Mass
As with Sundays, Catholics are oblicated to attend Mass in celebration of the particular Holy Day of Obligation. Whenever January 1, the solemnity of Mary, Mother of God, or August 15, the solemnity of the Assumption, or November 1, the solemnity of All Saints, falls on a Saturday or on a Monday, the precept to attend Mass is abrogated.
The Holy Day of Obligation Mass schedule for Holy Family can be found listed in the Bulletin and on the Parish Calendar for each of the feasts.
The Mass is the most holy act of religion; you can do nothing that can give greater glory to God or be more profitable for your soul than to hear Mass both frequently and devoutly.
(St. Peter Julian Eymard)
All the good works in the world are not equal to the Holy Sacrifice of the Mass because they are the works of men; but the Mass is the work of God. Martyrdom is nothing in comparison for it is but the sacrifice of man to God; but the Mass is the sacrifice of God for man.
(St. John Vianney)