The Bible is a book embedded in history. History is embedded in the Bible. Solomon and Hezekiah are historical figures that did historical things. Writing and editing were two of those historical activities. Many critics have pointed to some historical reference in the Bible and trumpeted about how the Bible was wrong only to be shown up as more research proved them wrong.
Yet having said that the Bible is not a history book. It is a book of salvation. The story of the birth of Jesus is in the book to proclaim that
(Galatians 4:4 KJV) But when the fulness of the time was come, God sent forth his Son, made of a woman, made under the law, to redeem them that were under the law, that we might receive the adoption of sons.It is not there for us to declare a national holiday and get off work. Jesus came to save us for eternity not give us a temporary rest. That may be why the Bible does not give us a specific date for the nativity.
So? Enjoy the day. Enjoy your family. Enjoy your holiday. Remember that the baby in the manger came to die on a cross to save us from our sins. Merry Christmas.