In the Dioceses of the United States, the following feasts are considered holy days of obligation:
In November 1991, the National Conference of Catholic Bishops approved a motion that 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. This action was confirmed by the Holy See on July 4, 1992.
Additionally, the Solemnity of the Ascension of the Lord is considered a holy day of obligation in the Dioceses of the United States. However, with the permission of the Holy See, each ecclesiastical Province was given permission to move the observance of this feast to the Seventh Sunday of Easter. This is the practice in the Province of Florida (the seven dioceses in the State of Florida).
In 2018 the following Holy Days of Obligation will be observed:
Wednesday, August 15 – Solemnity of the Assumption of the Blessed Virgin Mary
Thursday, November 1 – Solemnity of All Saints
Saturday, December 8 – Solemnity of the Immaculate Conception of the Blessed Virgin Mary
Tuesday, December 25 – The Nativity of our Lord and Savior Jesus Christ (Christmas)
[P.N. – In 2018, Saturday, December 8, the Solemnity of the Immaculate Conception occurs on a Saturday. In accord with the 1991 decision of the USCCB, this day is kept as a holy day of obligation, binding the faithful to attend Mass. Masses for this feast may be celebrated after 4:00 p.m. on December 7 and up to 2:00 p.m. on Saturday, December 8.