Morgen.so - All-in-one Calendar, Tasks & Scheduler. Morgen is the single hub for everything that revolves around time management.
Sun Surveyor - Sun Surveyor calculates Sun and Moon Positions, Sunrise & Sunset and Moonrise & Moonset...
Zoho Calendar - Zoho Calendar is a business calendar that comes along with the Zoho Mail suite of applications. Make your schedules click by effortlessly managing events with Zoho Calendar.
Suntimes - Android app (and widget collection) that displays sunlight and moonlight times for a given location.
Calbird - Simple, instant scheduling.
Sol: Sun Clock - Get reminded when it's sunrise or sunset, wherever you travel!