And it came to pass in those days, that there went out a decree from Caesar Augustus, that all the world should be taxed.
And this taxing was first made when Cyrenius was governor of Syria.
And all went to be taxed, every one into his own city.
And Joseph also went up from Galilee, out of the city of Nazareth, into Judaea, unto the city of David, which is called Bethlehem; because he was of the house and lineage of David:
To be taxed with Mary his espoused wife, being great with child.
And so it was, that, while they were there, the days were accomplished that she should be delivered.
And she brought forth her firstborn son, and wrapped him in swaddling clothes, and laid him in a manger; because there was no room for them in the inn.
Luke 2:1-7. The Holy Bible.
While the month and date of Jesus’ birth are unknown, by the early-to-mid 4th century, the Western Christian Church had placed Christmas on December 25, a date later adopted in the East. Today, most Christians celebrate Christmas on the date of December 25 in the Gregorian calendar, which is also the calendar in near-universal use in the secular world. However, some Eastern churches celebrate Christmas on the December 25 of the older Julian calendar, which currently corresponds to January 7 in the Gregorian calendar, the day after the Western Christian Church celebrates the Epiphany.
Source: wikipedia.org | The Holy Bible