Dawn (from an Old English verb dagian “to become day”) is the time that marks, depending on the specific usage, the beginning of the twilight before sunrise, the period of the pre-sunrise twilight or the time of sunrise. When identified as the beginning of or the period of twilight, it is recognized by the presence of weak sunlight, while the Sun itself is still below the horizon. […]

via The abduction and imprisonment of the dawn goddess, and her liberation — Cradle of Civilization