Dawn

Dawn is the period marking the start of morning twilight, before sunrise, beginning when the Sun center reaches eighteen degrees below the observer horizon and indirect sunlight first begins to scatter through Earth atmosphere. The period continues until sunrise itself, when the Sun upper edge crosses the horizon and direct daylight overtakes the earlier diffuse light. Dawn is distinct from both sunrise and morning: it is defined by the presence of scattered indirect daylight in the sky rather than by the Sun disc actually appearing. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/