The Sunday celebration of the Lord's Day and his Eucharist is at the heart of the Church's life."Sunday is the day on which the paschal mystery is celebrated in light of the apostolic tradition and is to be observed as the foremost holy day of obligation in the universal Church." Church law directs Catholics to their obligation to worship God on Sunday and Holy Days of Obligation by attending Mass. This follows from the fact that in the Mass it is Christ Himself who worships the Father, joining our worship to His. In no other way is it possible to adequately give thanks to God for the blessings of creation, redemption and our sanctification than by uniting our offerings to that of Jesus Christ Himself.

In addition to Sunday, the days to be observed as holy days of obligation in the Latin Rite dioceses of the United States of America, in conformity with canon 1246, are as follows:

1. Solemnity of Mary, Mother of God, January 1 (Unless on a Saturday or a Monday)

2. Solemnity of the Ascension, (Transferred to Sunday before Pentecost in this part of U.S.)

3. Solemnity of the Body and Blood of Christ (Transfered to 2nd Sun after Pentecost in the U.S)

4. Solemnity of the Assumption of the Blessed Virgin Mary, August 15 (Unless on a Sat or Mon)

5. Solemnity of All Saints, November 1 (Unless on a Saturday or a Monday)

6. Solemnity of the Immaculate Conception, December 8

7. Solemnity of the Nativity of Our Lord Jesus Christ, December 25

8. Solemnity of the Epiphany of the Lord (Transfered to 2nd Sun. after Christmas in the U.S.)

"On Sundays and other holy days of obligation, the faithful are to refrain from engaging in work or activities that hinder the worship owed to God, the joy proper to the Lord's Day, the performance of the works of mercy, and the appropriate relaxation of mind and body." (CCC,2185)

Sunday is traditionally consecrated by Christian piety to good works and humble service of the sick, the infirm, and the elderly. Christians will also sanctify Sunday by devoting time and care to their families and relatives, often difficult to do on other days of the week. Sunday is a time for reflection, silence, cultivation of the mind, and meditation which furthers the growth of the Christian interior life." (CCC,2186)

"Sanctifying Sundays and holy days requires a common effort. Every Christian should avoid making unnecessary demands on others that would hinder them from observing the Lord's Day." (CCC,2187)