With short days and limited daylight, it’s useful to have accurate times for dawn and dusk. I’ve been playing around with PyEphem and Flask to build Sundowner – a simple web app for calculating sunrise, sunset, and civil dawn and dusk1 for different locations.
The source can be found on GitHub, and can be installed from PyPi. I’m running the proof-of-concept with nginx and uWSGI.
Civil dawn/dusk is when the sun is 6º below the horizon – essentially when there’s enough light to travel safely. ↩