<P> With regard to a December religious feast of the sun as a god (Sol), as distinct from a solstice feast of the (re) birth of the astronomical sun, one scholar has commented that, "while the winter solstice on or around December 25 was well established in the Roman imperial calendar, there is no evidence that a religious celebration of Sol on that day antedated the celebration of Christmas". "Thomas Talley has shown that, although the Emperor Aurelian's dedication of a temple to the sun god in the Campus Martius (C.E. 274) probably took place on the' Birthday of the Invincible Sun' on December 25, the cult of the sun in pagan Rome ironically did not celebrate the winter solstice nor any of the other quarter - tense days, as one might expect ." The Oxford Companion to Christian Thought remarks on the uncertainty about the order of precedence between the religious celebrations of the Birthday of the Unconquered Sun and of the birthday of Jesus, stating that the hypothesis that December 25 was chosen for celebrating the birth of Jesus on the basis of the belief that his conception occurred on March 25 "potentially establishes 25 December as a Christian festival before Aurelian's decree, which, when promulgated, might have provided for the Christian feast both opportunity and challenge". </P> <P> As Christmas was unknown to the early Christian writers, it must have been introduced sometime after 300 . Irenaeus and Tertullian omit it from their lists of feasts, and Origen writes that in the Scriptures sinners alone, not saints, celebrate their birthday . Arnobius can still ridicule the "birthdays" of the gods . The first recorded Christmas celebration was in Rome in 336 . The feast was introduced to the Eastern Roman Empire after the death of Emperor Valens, who favored the Arian heresy, in 378 . </P> <P> In 245, Origen of Alexandria, writing about Leviticus 12: 1--8, commented that Scripture mentions only sinners as celebrating their birthdays, namely Pharaoh, who then had his chief baker hanged (Genesis 40: 20--22), and Herod, who then had John the Baptist beheaded (Mark 6: 21--27), and mentions saints as cursing the day of their birth, namely Jeremiah (Jeremiah 20: 14--15) and Job (Job 3: 1--16). In 303, 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 does not necessarily show that Christmas was not a feast at this time . </P> <P> The fact the Donatists of North Africa celebrated Christmas suggests that the feast was established by the time that church was created in 311 . The earliest known Christmas celebration is recorded in a fourth - century manuscript compiled in Rome . This manuscript is thought to record a celebration that occurred in 336 . It was prepared privately for Filocalus, a Roman aristocrat, in 354 . The reference in question states, "VIII kal . ian . natus Christus in Betleem Iudeæ". This reference is in a section of the manuscript that was copied from earlier source material . The document also contains the earliest known reference to the feast of Sol Invictus . </P>

When was december 25th chosen as christmas day