The New Testament Gospel of Luke may indirectly give the date as December for the birth of Jesus, with the sixth month of Elizabeth’s pregnancy with John the Baptist cited by John Chrysostom (c. 386) as a date for the Annunciation. Tertullian (d. 220) did not mention Christmas as a major feast day in the Church of Roman Africa. In Chronographai, a reference work published in 221, Sextus Julius Africanus suggested that Jesus was conceived on the spring equinox. The equinox was March 25 on the Roman calendar, so this implied a birth in December. Sextus Julius Africanus was the first to identify December 25, later to become the universally accepted date, as the date Jesus’s birth in 221. In 245, the theologian Origen of Alexandria stated that, “only sinners (like Pharaoh and Herod)” celebrated their birthdays. In 303, Christian writer Arnobius ridiculed the idea of celebrating the birthdays of gods, a passage cited as evidence that Arnobius was unaware of any nativity celebration. Since Christmas does not celebrate Christ’s birth “as God” but “as man”, this is not evidence against Christmas being a feast at this time. The fact the Donatists of North Africa celebrated Christmas may indicate that the feast was established by the time that church was created in 311.
Feast established
The earliest known reference to the date of the nativity as December 25 is found in the Chronography of 354, an illuminated manuscript compiled in Rome. In the East, early Christians celebrated the birth of Christ as part of Epiphany (January 6), although this festival emphasized celebration of the baptism of Jesus.
Christmas was promoted in the Christian East as part of the revival of Catholicism following the death of the pro-Arian Emperor Valens at the Battle of Adrianople in 378. The feast was introduced to Constantinople in 379, and to Antioch in about 380. The feast disappeared after Gregory of Nazianzus resigned as bishop in 381, although it was reintroduced by John Chrysostom in about 400.