The following days are observed as Holy Days of Obligation in Latin Rite Dioceses in the United States:
January 1 | The Solemnity of Mary, Mother of God
August 15 | The Solemnity of the Assumption of the Blessed Virgin Mary
November 1 | The Solemnity of All Saints
December 8 | The Solemnity of the Immaculate Conception
December 25 | The Solemnity of the Nativity of Our Lord Jesus Christ (Christmas)
In 1991, the U.S. Catholic Bishop decreed that there is no obligation in the U.S. to attend Mass when the following fall on a Saturday or Monday:
In the Diocese of Green Bay and most dioceses in the country, the Solemnity of the Ascension is celebrated on the Seventh Sunday of Easter.
The Ascension is celebrated on Thursday of the Sixth Week of Easter in these states: Connecticut, Maine, Massachusetts, Nebraska, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, and Vermont.
The Solemnity of the Ascension remains a Holy Day of Obligation in the U.S. regardless of which day a diocese observes it.