In stanza 25 of Vafþrúðnismál, the jötunn Vafþrúðnir answers Odin's question about the origin of day. He states that Delling is the father of day while night was born from Nörvi. This exchange establishes a genealogical framework for the concept of time in Norse myth. The text describes how beneficent powers created new and waning moons to help men count years. In stanza 12 of the same poem, the horse Skinfaxi draws day to mankind with its gleaming mane. Later verses in Sigrdrífumál reference the sons of Dagr alongside a female relative of Nótt. A prayer spoken by the valkyrie Sigrdrífa invokes these figures after Sigurd wakes her from a sleep curse. The poem Hrafnagaldr Óðins depicts the son of Delling urging on his horse adorned with precious jewels. Over Mannheim shines the steed's mane as it dewes in the chariot.
Snorri's Narrative Framework
Chapter 10 of Gylfaginning presents Dagr as the son of Dellingr and his wife Nótt. High, an enthroned figure, explains that Dagr is as bright and beautiful as his father's people. Odin gave both Dagr and his mother Nótt a chariot and a horse each. Dagr received Skinfaxi whose mane illuminates all the sky and the Earth. They ride around the Earth every twenty-four hours. Chapter 24 of Skáldskaparmál identifies Dagr as a brother of Jörð. This text also notes that Skinfaxi or Glad pulls forth the day. In chapter 58, Dagr appears as one of various words for time. These passages personify the abstract concept of daylight into a divine character within the narrative structure.Manuscript Discrepancies
Scholar Haukur Thorgeirsson highlights conflicting genealogical accounts across four manuscripts of Gylfaginning. The oldest manuscript U lists Jörð as the wife of Dellingr and the mother of Dagr. Manuscripts R, W, and T cast Nótt in the role of Dellingr's wife and Dagr's mother instead. Thorgeirsson argues that the version in U resulted from an accidental shortening of a text similar to that found in RWT. This scribal error allowed the altered family tree to enter Icelandic poetic tradition. The variation suggests scribes modified source material differently over centuries. Such discrepancies complicate efforts to reconstruct a single authoritative mythological lineage.The Svipdagr Hypothesis
Otto Höfler theorized that Dagr may be related to the hero Svipdagr whose name means suddenly dawning day. This figure appears in two poems compiled together known as Svipdagsmál in the Poetic Edda. He is also attested by the name Swæfdæg in the mythical genealogies of Anglian houses of Anglo-Saxon England. Höfler proposed that Svipdagr might have been a Dagr of the Suebi. Family members named Sólbjartr meaning sun-light indicate a potential god of the skies. Gróa meaning growth points to a possible goddess of growth. His wooing of Menglöð often identified with the goddess Freyja supports the idea of him being a fertility god.