On the ceiling of the cenotaph of Seti I at Abydos, the Book of Nut is preceded by columns of hieroglyphs under vignettes. This collection of texts has been named “Text of the Clock” because it describes a shadow clock together with some explanations concerning functioning. The contents of these columns are closely linked to the Book of Nut, since its subject is the cycle of the decans and the use of these stars to determine the hours of the night.