Dies Luminum

Dies Luminum (ἠμέρα φώτων, day of lights), an ancient name for the Epiphany; baptism being generally called φῶς and φώτισμα, light and illumination, this day, being the supposed day of our Savior's baptism, was styled "the day of lights or illumination, or baptism." Asterius Amasenus (Hom. 4, in Fest. Kal. cited by Bingham) says, "We celebrate the nativity because at this time God manifested his divinity to us in the flesh. We celebrate the feast of light, because, by the remission of our sins in baptism, we are brought, as it were, out of the dark prison of our former life to a life of light and virtue." — Bingham, Orig. Eccles. bk. 20, ch. 4, § 7.