This is the first comprehensive study in English of early Christian methods for calculating the phases of the moon and the date for Easter Sunday to have appeared in more than one hundred years. It offers a new explanation of how the system of numbering the years AD (Anni Domini, Years of the Lord) originated.

• I: Contexts


• 1: Introduction


• 2: Chronological Systems


• 3: Easter and the Passover Moon


• II: The Easter Tables of Dionysius Exiguus


• 4: The Letters to Boniface and Petronius


• 5: The Structure of the 19-year Cycle


• 6: The Computistical Rules


• III: Paschal Calculations in Early Christianity


• 7: The 8-year Cycle and the Invention of the Epacts


• 8: The 19-year cycle of Anatolius


• 9: Athanasius and the Council of Sardica


• 10: The Classical Alexandrian Cycle


• 11: Paschal Calculations at Rome


• 12: Paschal Calculations in the Eastern Empire


• 13: The Chronicon Paschale and the origins of the Byzantine era


• IV: The Origins of the Christian era


• 14: Evidence for the chronology of Jesus


• 15: The Christian era of Dionysius Exiguus


• 16: The Christian era of Panodorus


• 17: The Christian era of Julius Africanus


• 18: Anatolius and the Christian era


• Bibliography


• Index