Go to Mass every Sunday and on Six other days during the year. These six days are called "Holy Days of Obligation".
Days on which Catholics are obliged under pain of mortal sin to attend Mass and to abstain from all unnecessary servile work. Every SUNDAY in the year is a Holy Day of Obligation. In addition, Church Law has declared certain other great feast days as holy days. These may vary between countries according to the rulings of the Holy See.
In the United States the Holy Days Of Obligation are:
Solemnity of Blessed Virgin Mary
Feast of Circumcision
Thursday of the Sixth Week of Easter
Forty Days After Easter
Assumption of the Blessed Virgin Mary
All Saints Day - Solemnity
Immaculate Conception - Solemnity
Christmas Day - Solemnity
The National Conference of Catholic Bishops confirmed the following action on July 4, 1992:
Whenever January 1, the Solemnity of Mary Mother of God or August 15, the feast of the Assumption of the Blessed Virgin or November 1, the Feast of all Saints falls on a Saturday or a Monday, the precept to celebrate Mass is dispensed.