Ditto to the above comments, well done. I live in a city in the north of China, and the sun disappears into the smog zone about 10 degrees above the horizon, and after that it's pretty well over - the pollution is too dense to allow much reflective bathing of clouds etc. There's a useful piece of software available for download known as 'The Photographer's Ephemeris' (http://photoephemeris.com/), will tell you sunrise & sunset & moon phases based on your location.