According to the Catholic Community Television Network...
Every Catholic who has attained the age of reason, and is not prevented by sickness or other sufficient cause, is obligated to rest from servile work and attend Holy Mass on the following days. In so far as possible they are also to abstain from these labors and business concerns which impede the worship to be rendered to God, the joy which is proper to the Lord's Day, or the proper relaxation of mind and body.
All Sundays of the year.
January 1, the Octave of Christmas, Solemnity of Mary, Mother of God
The Ascension of Our Lord, 40 days after Easter
August 15 - The Assumption of the Blessed Virgin
November 1 -All Saint's Day
December 8 - The Immaculate Conception of the Blessed Virgin Mary
December 25 - Christmas -The Nativity of Our Lord