Today is the seventh day in the octave of Christmas. The Church celebrates the optional memorial of St. Sylvester I, pope and confessor. He ruled the Church during the reign of Constantine when the Arian heresy and the Donatist schism had provoked great discord. He convoked the first Ecumenical Council of Nicaea.
Numerous legends dramatize his life and work, e.g., how he freed Constantine from leprosy by baptism; how he killed a ferocious dragon that was contaminating the air with his poisonous breath. Such legends were meant to portray the effects of baptism and Christianity's triumph over idolatry. For a long time the feast of St. Sylvester was a holyday of obligation. The Divine Office notes: He called the weekdays feria, because for the Christian every day is a "free day" (the term is still in use; thus Monday is feria secunda.).