A decree is ascribed to him appointing the four fasts of the Ember seasons, but his name is best known in connection with the old cemetery on the Appian Way, which was enlarged and adorned by him, and is called to this day the Catacomb of St. Callistus.
During the persecution under the Emperor Severus, St. Callistus was driven to take shelter in the poor and populous quarters of the city; yet, in spite of these troubles, and of the care of the Church, he made diligent search for the body of Calipodius, one of his clergy who had suffered martyrdom shortly before, by being cast into the Tiber. When he found it he was full of joy, and buried it, with hymns of praise. Callistus was martyred October 14, 223.
Feast Day of Saint Callistus
The Feast Day of Saint Callistus is October 14. The origin of Feast Days: most saints have specially designated feast days and are associated with a specific day of the year and these are referred to as the saint's feast day.
The feast days first arose from the very early Christian custom of the annual commemoration of martyrs on the dates of their deaths at the same time celebrating their birth into heaven.