The holy days of obligation extend the spirit of Sunday into the great feasts of the year, so that the
chief mysteries of the faith are celebrated by the whole Church together. They are kept as Sundays
are: by hearing Mass and by abstaining from unnecessary servile work. In the United States, by
decree of the Third Plenary Council of Baltimore, there were six: the Circumcision of Our Lord
(January 1), the Ascension (forty days after Easter), the Assumption of the Blessed Virgin (August
15), All Saints (November 1), the Immaculate Conception (December 8), and Christmas
(December 25). Each one sets before us a mystery of Christ, of His Mother, or of His saints, to be
honored not only by attendance but by joy.