What is simple-calendar?

Simple Calendar is an open-source calendar app for Android that works entirely offline. It was built with the goal of covering everything a personal calendar needs, without ads, without unnecessary permissions, and without requiring an internet connection to function. The source code is publicly available, and the app has been translated into more than 30 languages. The app covers the full range of standard calendar use cases: scheduling one-time events, setting up repeating events with custom rules, adding reminders, and viewing your schedule in daily, weekly, monthly, yearly, or simple list formats. You can import birthdays and anniversaries from your contacts, import public holidays, and view event locations on a map. Sharing events with others through email or messaging apps is built in. For people who want cloud sync, the app supports CalDAV, a widely used calendar protocol. This means it can sync with Google Calendar, Microsoft Outlook, Nextcloud, Exchange, and other services that speak the same protocol. Events can also be exported and imported as .ics files, which is the standard format most calendar services understand. Customization is a central feature. You can change the app's color themes, adjust reminder sounds and vibration patterns, and configure widget appearance for your home screen. Settings can be exported to a file and moved to another device, which makes switching phones less disruptive. The project is available through F-Droid, an app store specifically for free and open-source Android software, in addition to the usual release channels. It accepts donations through PayPal, Patreon, and several cryptocurrency addresses listed in the README.