The Sunrise Sunset Calculator is a free application that lets you find the following timings for either your current location or any given location on the earth: 1) Sunrise and sunset 2) Civil Dawn and Dusk 3) Nautical Dawn and Dusk 4) Astronomical Dawn and Dusk The computation is done using the formulae at http://www.edwilliams.org/sunrise_sunset_algorithm.htm. Note that since these formulae do not take into account the elevation of the place, the computed values may be slightly inaccurate f