The Lord’s Day, on which the paschal mystery is celebrated, is by apostolic tradition to be observed in the universal Church as the primary holy day of obligation. In the same way the following holy days are to be observed: the Nativity of Our Lord Jesus Christ, the Epiphany, the Ascension of Christ, the feast of the Body and Blood of Christ, the feast of Mary the Mother of God, her Immaculate Conception, her Assumption, the feast of St. Joseph, the feast of the Apostles [Saints] Peter and Paul, and the feast of All Saints (canon 1246 §1).
However, the episcopal conference may, with the prior approval of the Apostolic See, suppress certain holy days of obligation or transfer them to a Sunday (canon 1246 §2).