The tradition for December 25th is actually quite ancient. Hippolytus, in the second century A.D., argued that this was Christ's birthday. Meanwhile, in the eastern Church, January 6th was the date followed.But in the fourth century, John Chrysostom argued that December 25th was the correct date and from that day till now, the Church in the East, as well as the West, has observed the 25th of December as the official date of Christ's birth.