Nott is the personification of night in Norse myth, a giantess (jotunn) who rides across the sky in a chariot drawn by the horse Hrimfaxi, Frost-mane, from whose bit the dew is said to fall each morning. In Snorri's account she is dark as befits her kin, and by her third husband Dellingr she is mother of Dagr, Day, who rides after her on the shining horse Skinfaxi whose mane lights the sky, so that night and day are a mother and son circling the heavens in turn.
The scheme, set out in the poem Vafthrudnismal and elaborated by Snorri, is characteristic of Norse cosmology's habit of assigning a driving figure to each recurring feature of the sky. Nott has no cult; she is a figure of cosmological poetry rather than of worship. Nott's genealogy varies between sources: Snorri gives her three successive husbands, ending with Dellingr, father of Dagr, while the eddic poem Vafthrudnismal names her more simply as daughter of the giant Norvi, a discrepancy typical of the way Norse cosmological genealogy could be elaborated differently by different tellers without any single version being treated as final. Her horse Hrimfaxi, Frost-mane, is paired directly with Dagr's horse Skinfaxi, Shining-mane, in the same eddic poem, so that the entire day-night cycle is imagined as two riders and their mounts completing an endless circuit of the sky rather than as an abstract alternation.