What is Twilight?
[[Image:July midnight in Lapland.jpg|thumb|right|200px|Twilight view.]] [[Image:Little Gasparilla sunrise.jpg|thumb|right|200px|Sunrise on Placida Harbour, Florida]] {{for|the book series by Stephenie Meyer|Twilight (series)}} '''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]]. == Other websites == {{commons|Twilight}} *[http://www.usno.navy.mil/USNO/astronomical-applications/astronomical-information-center/rise-set-twi-defs Definition of Twilight] {{Webarchive|url=https://web.archive.org/web/20110606224804/http://www.usno.navy.mil/USNO/astronomical-applications/astronomical-information-center/rise-set-twi-defs |date=2011-06-06 }}, US Naval Observatory *[http://aa.usno.navy.mil/data/docs/RS_OneYear.html Twilight time calculator] {{Webarchive|url=https://web.archive.org/web/20061205022001/http://aa.usno.navy.mil/data/docs/RS_OneYear.html |date=2006-12-05 }} *[http://herbert.wikispaces.com/Length+of+Day Formulae to calculate twilight duration] {{Webarchive|url=https://web.archive.org/web/20080915082738/http://herbert.wikispaces.com/Length+of+Day |date=2008-09-15 }}, by Herbert Glarner [[Category:Parts of a day]] {{stub}}