"1. And the angel of the presence spake to Moses according to the word of the Lord, saying: Write the complete history of the creation, how in six days the Lord God finished all His works and all that He created, and kept Sabbath on the seventh day and hallowed it for all ages, and appointed it as a sign for all His works. 2. For on the first day He created the heavens which are above and the earth and the waters and all the spirits which serve before him -the angels of the presence, and the angels of sanctification, and the angels [of the spirit of fire and the angels] of the spirit of the winds, and the angels of the spirit of the clouds, and of darkness, and of snow and of hail and of hoar frost, and the angels of the voices and of the thunder and of the lightning, and the angels of the spirits of cold and of heat, and of winter and of spring and of autumn and of summer and of all the spirits of his creatures which are in the heavens and on the earth, (He created) the abysses and the darkness, eventide <and night>, and the light, dawn and day, which He hath prepared in the knowledge of his heart. 3. And thereupon we saw His works, and praised Him, and lauded before Him on account of all His works; for seven great works did He create on the first day." Jubilees ch. 2
This I consider sacred authoritative Scripture and it explicitly confirms a literal 7 day creation, and also explicitly proves wrong the gap theory of a creation before this creation. On the first day God created the heavens and the earth.
I have, I would say, compelling evidence that Yehoshua accepted the Book of Jubilees as true Scripture, that he endorsed it as real history and prophecy about himself, which I have covered in this paper of mine:
https://www.academia.edu/17164690/B..._Anointed_One_in_Gospel_according_to_John_7-8
The New Testament also says that the Law was given through angels which is nowhere explicitly found in in the traditional OT canons except the Ethiopian Orthodox one which contains Jubilees. The only other ancient writer that I can think of that said this was Josephus. So there was a Jewish tradition about this. But I'm betting it had its origin in the Levitical Priesthood, in which this book would have been in their care, teaching the People this, as is witnessed by the Dead Sea Scrolls, which certain scholars like Rachel Ellior, believe that the Qumran sect started with the genuine ousted Levite priests, the sons of Zadok, and that the original calendar of the Israelites was the solar calendar of Enoch.