Twilight

Twilight view.

Sunrise on Placida Harbour, Florida

Twilight means either dawn (in the morning) or dusk (in the evening).

In the morning, dawn is when it is not dark any more, and the light of the sun is just starting to appear, before sunrise. In the evening, it is the other way around and that phenomenon is called dusk. At sunset, the sun disappears, and darkness is settling in. Light fades away.

The following have been defined:

Civil twilight is when the sun is less than 6° below the horizon. It ends at sunrise in the morning or follows sunset in the evening.
Nautical twilight is when the sun is between 6° and 12° below the horizon.
Astronomical twilight is when the sun is between 12° and 18° below the horizon.

For all these definitions, the horizon is at sea level.

Twilight Media

Twilight is the time period between dawn and sunrise, or between sunset and dusk.
Morning twilight: astronomical, nautical, and civil stages at dawn. The apparent disk of the Sun is shown to scale.
Evening twilight: civil, nautical, and astronomical stages at dusk. The solar disk is shown to scale.
Midtown Manhattan during civil twilight, demonstrating blue hour
Civil twilight in a small town in the Mojave Desert
Toronto, Canada, seen across Lake Ontario at twilight. Taken from the end of the pier at Port Dalhousie, Ontario, with Toronto's CN Tower 51 km distant. The ship on the lake is approximately 5-10 km away.
Long exposure of nautical twilight in a small town in the Mojave Desert
At the beginning of nautical twilight, artificial lighting must be used to see terrestrial objects clearly.
A small town in the Mojave desert at dusk.
Astronomical twilight (dusk) with a crescent moon, as seen from Kuala Lumpur, Malaysia
Timelapse video of twilight and sunrise in Gjøvik in February 2021