Sunday, January 20, 2008

Twilight hours and a sunrise/sunset calculator

Stumble Upon Toolbar
A sunrise calculator for Canada can be found here.

This calculates Civil and Nautical twilight but not Astronomical twilight. For definitions, see here.

Astronomical twilight occurs after Nautical twilight by about the same amount of time as Nautical follows Civil. For example, twilight in Toronto for Earth Hour 2008 (Eastern Daylight Time) will be
  • Sunset - 7:41pm
  • Civil - 8:10pm
  • Nautical - 8:44pm
  • Astronomical - 9:20pm
A more complete (and complex) calculator can be found here.

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