Position of the sun and moon were the main sign posts with adjustments periodically for the 360 day year as the seasons would fall out of line over 40 years or so(over 40 years=200 days). Psssover was set via special lunar stipulations yearly.
Are the position of Moon and the Sun signs in the heavens? Does the position of stars in the background of the solar bodies locate the solar system bodies, like a clock turning past the markings of its face?