Since Christ was not just fully divine, He was also fully man that is, to take on a true flesh and soul. Christ’s mother Mary bore Him in the presence of Joseph and the Shepards and animals thereof. In the Icons, the nativity is often depicted in a cave with the three Magi, Joseph, and the Mother of God herself, often resting gracefully after the birth itself. As far as the monastic charter is concerned, many Orthodox fast (you’re essentially vegan) for forty days prior to Christmas in spiritual preparation for the feast day.
If you don’t know, historically accurate St. Nicholas is better than whatever consumerist abomination “Santa Claus” is. St. Nicholas was born in Myra, Greece and was ordained as a priest by his uncle who at that time was the residing bishop. Upon his ordination, he frequently distributed wealth to the poor, his legendary philanthropy is what attributed him to great generosity. The story he is most well known for is the time he was able to pay off the dowries of three women so that they could marry, not marrying would’ve most likely meant a reliance on prostitution. He then (but many scholars continue to debate this) attended the council of Nicaea in 325 where he slapped Arius out of his great love for the truth. Arius was proposing the Aryanism heresy which proposed Christ as a subordinate to God The Father. In short, tell you’re family about real St. Nicholas slapping heretics as you sit around the fireplace, happy holidays!