Dawn, Sunrise, Twilight, Sunset, and Dusk

Dawn occurs before sunrise, before the top of the Sun reaches the horizon.

Twilight is the name given to the period between dawn and sunrise, or between sunset and dusk, when light is still visible in the sky due to sunlight scattering off the atmosphere.

Sunrise and sunset are the points at which the top edge of the Sun reaches the horizon; the only difference between them is the direction in which the Sun is moving at the time. It actually occurs when the top of the Sun is 0.57° below the horizon due to refraction of the Sun’s light by the atmosphere.
Dusk occurs after sunset, once the top of the Sun has passed the horizon.


Dawn, dusk, and twilight can also be separated in astronomical, nautical, and civil sections by how far below the horizon the Sun is (18°, 12° and 6° below the horizon respectively).