In Greek mythology Hemera was the personification of ay and one of the Protogenoi or primordial deities. She is the goddess of the daytime and, according to Hesiod (Theogony, 124-125), the daughter of Erebos and Nyx (the goddess of night). Hemera is remarked upon in Cicero's De Natura Deorum (3.17), where it is logically determined that Dies (Hemera) must be a god, if Uranus is a god. The poet Bacchylides states that Nyx and Khronos are the parents, but Hyginus in his preface to the Fabulae mentions Khaos as the mother/ father and Nyx as her sister.