...This ability to predict celestial events was the likely inspiration to depict astronomers as magicians, a caricature of the fact that they were really the scientists of their times and had nothing to do with supernatural abilities. Even during the era when the Westcar Papyrus was written, astronomers had already acquired this abstracted attribute. There, we read about the magician Djedi, who could behead a bull and then reattach the head. This, of course is a stellar metaphor just like the rest of that tale which is perfectly in line with the idea that decans had already been developed by the time of Khufu. The decans are the "cut" lines which divided constellations in this way "beheading" the bull, the goose (Cygnus?), and the bird (Aquilla?), yet they still "marched" the decan walk from east to west night after night just as they keep walking in front of Khufu in the tale.
The ability to predict events in the sky then was exactly the kind of demonstration of power Khufu would have needed to prove his status as a living god among the people of Egypt. And the super-star of Egyptian celestial events was the heliacal rising of Sirius. Was a revolutionary new measure of time at hand which could time the day of Sirius-Rising? Let's construct one from the elements likely known then. Above, we started with the decans, a 360-degree grid which divided the sky into discrete units of night time just like the face of a clock is divided into hours and minutes of discrete time.
If the decans were like the face of a clock and the constellation Taurus was the 12 o'clock marker, then we still need a moving cursor, the hand, to mark the time. With this star clock, we then can attempt to synchronize this measure of time with the heliacal rising of Sirius. The best way to count time in order to time a stellar event is to use the movement of an object in the sky which itself is mapped onto the stars, and not the Sun or a man-made scheme of time. And the most suitable object in the night-sky to monitor time is the Moon!...