Book of Jashar

Over Christmas I was watching Rex’s series “What your pastor doesn’t want you to know.” Its oriented towards the traditions of the Christmas holiday, and what are the origins of them. I encourage all to watch it if you have not already. If I where to sum it up in a quick description, which does not do it justice, nearly all the things I associate with the holiday originate with the pagan worship of Nimrod. When you think of it birthdays aren’t really mentioned in the bible and the 3 references I know the birthdays celebrations are put in a negative context. If god wanted us to put so much emphases on them , I would have thought Abrahams, Moses and David’s would be mentioned? This has lead me down a rabbit hole of studying Nimrod of the tower of Babel fame , the first Man to create a kingdom and put a crown upon his head, and Babylon. In my bible, I am sure this depends on translation, it says he was a mighty hunter. In the context of my mindset in today’s social construct, I am like Cool! I like hunting so I think this is a good thing right? Well they really mean he was a hunter of men and their souls, was a tyrant and did horrid, horrid things. This curiosity has lead me to the Book of Jashar. I had never heard of this book but I remember it being referenced in Joshua 10 when god stopped the sun and the moon so the Israelites could continue their route in battle and destroy the Armorites. A quick glance into the book of Jashar gave me details that I was intrigued with. When building the tower of babel there was about 600,000 people involved with its construction. It also gives information on the peoples mindset, like if someone was to fall to their death in constructing the tower no one would even weep them, but if one brick was broken the entire people would mourn the loss of material. I have stopped studying the book of Jashar any further because I am looking for Rex’s and other guidance. Is the book a verified source of truth? Or is it a slightly referenced form of deception used to ensare people that want to geek out of details? Please let me know your thoughts and beliefs, thanks.