By Water & Blood

Panarion 51, Chapter 24: Calendar equivalences for birth and baptism

For he having been born in the month of January—that is, on the eighth before the Ides of January, which according to the Romans is the fifth of January evening into the dawning sixth; according to the Egyptians Tybi the eleventh; according to Syrians or Greeks Audynaios the sixth; according to Cypriots or Salaminians of the fifth month the fifth; according to Paphians of Julius the fourteenth; according to Arabs of Aleom the twenty-first; according to Cappadocians of Atarta the thirteenth; according to Athenians of Maimakterion the fifth; according to Hebrews of Tebeth the fifth—

for here too what was spoken by the prophet had to be fulfilled: ‘The ark of God entered among us’ (he means the perfect becoming-human of Christ) ‘on the fifth of the fifth month,’ as it was then fulfilled among the Hebrews; which first had to be fulfilled by the reckoning of the Hebrews,

which many of the nations also followed—I mean the Romans, who celebrate it as the fifth evening into the dawning sixth; and the Cypriots keep it as the fifth day of the month; and the Egyptians by nature, and the Salaminians, also keep the month itself as fifth, as the Hebrews also set it fifth from the new year observed among them—

he therefore passed through the aforesaid consulships twenty-nine complete, and in the thirtieth consulship, I mean about the eleventh month, he came to John and was baptized in the Jordan river in the thirtieth year of his incarnate birth, on the sixth before the Ides of November,

that is, according to the Egyptians Athyr the twelfth; according to the Greeks Dios the eighth; according to the Salaminians who are also Constantians of the third Choiak the sixth; according to Paphians of Apogonikos the sixteenth; according to Arabs of Angathalbaeith the twenty-second; according to Macedonians of Apellaios the sixteenth; according to Cappadocians of Aratata the fifteenth; according to Athenians of Metageitnion the seventh; according to Hebrews of Marheshvan—as the holy Gospel according to Luke bears witness to my account, as I have often said, speaking somehow thus: ‘And Jesus was beginning to be about thirty years old, being the son, as was supposed, of Joseph’;

and from that point, from Athyr the twelfth, ‘proclaiming the acceptable year of the Lord,’ according to what was previously spoken in the prophet Isaiah: ‘The Spirit of the Lord is upon me, because he has anointed me to preach good news to the poor; he has sent me to proclaim release to captives and recovery of sight to the blind, to proclaim the acceptable year of the Lord and a day of recompense.’