The Blue Hour describes a period of dawn and dusk, when the sky is colored specially which is very interesting for photography. The duration and timing of the Blue Hour varies depending on location and on the date. In order to achieve optimum results and to plan in advance the app Blue Hour (solar calculator) has been developed. The calculations are not only limited to the blue hour. Further information for sun and moon events can also be calculated. This includes information about sunrise, sunset together with data of the blue hour, golden hour and twilight times (civil, nautical and astronomical). Furthermore you can calculate information about moonrise, moonset and moon phases (calculated data are approximations of +/- 1 day accuracy). In this app you can view data for multiple locations. These can be defined manually or automatically by getting your GPS location. Additionally you have the opportunity to manually set timezones of the locations, which can be helpful if you are planning trips to locations with another timezone than the one, where you currently are in. Core features at a glance ☀️ Calculation of sunrise, sunset and solar noon 🌗 Calculation of moonrise and moonset + moonphase 🌠 Calculation of civil blue hour 🌌 Calculation of twilight times (civil, nautical and astronomical) 🌅 Calculation of golden hour 💫 Visualization of the azimuth-data of sunrise, sunset, moonrise and moonset 💫 Visualization of the azimuth-data of sun and moon for specific time 🌦️ 5 days weather prediction ❖ definition of multiple locations, including current position (based on GPS) ❖ monthly forecast ❖ export of forecast-data to Excel-tables ❖ reminder for events ❖ homescreen widget Note: the calculated values are approximations to plan your photography trips. Additionally it depends on weather situation, how good or if the blue or golden hour is visible.