This is one of the books found in the Library of Water. It is the first time the name of the planet is mentioned, Morgrad, and it contains information about the astronomical events. This is one of the books cited as references, do to the important lore it contains.
In the center lies the Morgrad, containing the four elements earth, water, fire and air. It is the place of the transience, the heart of the inexplicable darkness of Beliar. Above all this towers the sphere of heavens.
In the hierarchy of the universe, man is a receiver. His soul allows him to take part in the highest plane of existence, the divine spirit. Yet man's body is made from the substance of the Morgrad. He is a reflection of the world itself.
The synodic orbit of the planets, that is the course they take between two identical positions in relation with the Morgrad of our world, varies by just a few degrees every century. We therefore conclude that we are constantly moving with the rest of the universe.
When we created the first calendar we observed the course of the moon to determine the length of the solar year.