This article looks at cases of borrowing between astronomical and hemerological texts as seen particularly in the Wu xing zhan 五星占 manuscript from Mawangdui tomb 3 (168 BCE) and the daybook from Zhoujiatai tomb 30 (3rd cent. BCE). In short, we see evidence of astronomical knowledge enter into hemerology, where it is schematised to function as a sort of idealised game board for mantic functions to skip and pass through to determine the auspiciousness of times and directions. These schemes then find there way back into astronomical texts, where they project more or less unrealistic patterns onto celestial bodies.