Coptic Christmas is observed on what the Julian Calendar labels 25 December, a date that currently corresponds with 7 January on the more widely used Gregorian Calendar (which is also when Christmas is observed in Eastern Orthodox countries such as Russia). The 25 December Nativity of Christ was alleged very early by Hippolytus of Rome (170–236) in his Commentary on Daniel 4:23: "The first coming of our Lord, that in the flesh, in which he was born at Bethlehem, took place eight days before the calends of January, a Wednesday, in the forty-second year of the reign of Augustus, 5500 years from Adam." Another early source is Theophilus Bishop of Caesarea (115–181): "We ought to celebrate the birth-day of our Lord on what day soever the 25th of December shall happen." (Magdeburgenses, Cent. 2. c. 6. Hospinian, de origine Festorum Christianorum). However, it was not until 367 that 25 December began to be universally accepted. Before that, the Eastern Church had kept 6 January as the Nativity under the name "Epiphany." John Chrysostom, in a sermon preached in Antioch in 387, relates how the correct date of the Nativity was brought to the East ten years earlier. Dionysius of Alexandria emphatically quoted mystical justifications for this very choice. 25 March was considered to be the anniversary of Creation itself. It was the first day of the year in the medieval Julian calendar and the nominal vernal equinox (it had been the actual equinox at the time when the Julian calendar was originally designed). Considering that Jesus was thought to have been conceived on that date, 25 March was recognized as the Feast of the Annunciation which had to be followed, nine months later, by the celebration of the birth of Christ, Christmas, on 25 December.