The Book of Astronomy, also called the Astronomical Book or the Book of the Luminaries, is one of the oldest portions of the Book of Enoch — possibly predating the other sections by centuries. In it, the angel Uriel shows Enoch the movements of the sun, moon, and stars and explains how the cosmos keeps time.
The cosmology Enoch describes is pre-Copernican: the sun and moon are carried in chariots through gates in the sky, rising from one set of gates and setting at another, with the gates shifting through the year to produce the changing seasons. The stars have assigned paths. The winds come from specific corners of heaven. Everything is ordered, precise, and governed by divine law.
But within this ancient cosmology is something theologically profound: the insistence that the universe runs on precise sacred time. The solar year of 364 days — 52 weeks, exactly — is the divine calendar. Every sacred observance has its proper day, and those days were built into the structure of creation from the beginning. Getting the calendar right isn't a minor technical matter. It's the difference between worshipping God at the times he appointed and worshipping him at the wrong times.
This conviction — that sacred time is built into cosmic structure, not invented by human convention — is one of the most distinctive aspects of the Enochic tradition. It's also one of the reasons the community at Qumran, which possessed the Book of Enoch and the Book of Jubilees, maintained its own calendar in opposition to the mainstream Jewish calendar. For them, the calendar wasn't a matter of tradition. It was a matter of obedience.