Answer:
Our word Christmas comes from the middle age use " Christ Mass' and is central to the celebration of the Nativity. This was established in the year 600 and in Medieval England there were 3 masses celebrated on Christmas Day. The first was at midnight (Angel's Mass) representing that the light of salvation appeared at the darkest moment of the darkest date of winter. The second Mass came at dawn ( Shepherd's Mass) and the third during the day ( Mass of the Divine Word). The season of Advent was 40 days leading up to Christmas and St. Nicholas was a very popular Medieval saint. His feast day came in Advent ( December 6), but Santa didn't show until after the Reformation.
Also important was the Christmas banquet. The menu varied with soups, stews, birds, fish, breads, puddings and the common element among all was the Yule boar. This was the animal for those who could afford it, but if they couldn't it was a pie shaped like a boar. Churches and houses were decorated with ivy, mistletoe, holly and anything green which stayed up until the eve of Candlemass. Gifts were given by the New Year Gift and was an Roman tradition. The Christmas present wasn't part of the a Medieval Christmas.
A medieval Christmas was not over in a day and went on to January 6 with the Feast of the Epiphany on the 12th day after Christmas. This celebrated the visit from the Wise Men and the manifestation of Christ to the Gentiles. The Monday after Epiphany was called Plough Monday and it was when ploughing began.