Civil Twilight Calculator

Everyone who works outside needs to know about daylight hours! Pilots often need to know when night occurs. The FAA uses several different times of day for calling night vs. day, depending on the purpose. Most Apps find the twilight times by going to a database on the internet. That means you need a network connection to use them. This app is unique because it does all the celestial calculations internally! No internet required! Find the start of night at your destination while you are stil