I hazarded a guess at half an hour, based on the fact that the sky was light and the birds were singing about 30 minutes before I saw the sun's rays hit mount Maroma, turning it a beautiful pink. I also had a vague remembrance from my years at White Waltham airfield (not flying, rest easy) that technically, non night-rated pilots could fly until half an hour after sunset. My rationale being that that must officially be dusk, ergo dark. Whether that is a correct remembrance, I cannot tell you.
A quick look on the internet and I found this website http://www.gaisma.com/en/ It gives the dawn, sunrise, sunset and dusk times for the world.
This is a very useful tool for writers who want to make sure that their plot does not disintegrate because of a few misplaced minutes.
|Sunset in Sedella|