Etar

Overview

Etar is a complete, open-source replacement for Google Calendar designed specifically for Android users who want to regain control over their personal schedules. Based on the Android Open Source Project (AOSP) calendar but significantly enhanced with modern features and a refined UI, Etar provides a familiar experience without the privacy compromises associated with big-tech ecosystems.

Unlike Google Calendar, which logs your appointments and locations on corporate servers, Etar acts as a shell for your data. It doesn’t have its own cloud; instead, it utilizes the Android calendar database. This allows you to keep your calendar entirely offline or sync it with a privacy-respecting backend of your choice, such as Nextcloud or a self-hosted Radicale server.

Key Features

Material Design Interface

Etar offers a beautiful, minimalist interface that follows modern Android design guidelines. It supports dark mode, customizable theme colors, and fluid transitions, making it one of the most aesthetically pleasing open-source calendars available.

Flexible View Options

Whether you need to see your entire month at a glance or focus on your hourly agenda, Etar provides multiple viewing modes. The “Agenda” view is particularly powerful for those with busy schedules, providing a chronological list of upcoming events.

Seamless Sync Integration

While Etar can function as a 100% offline calendar, it excels when paired with sync adapters. By using Etar alongside apps like DAVx5, you can sync your events with any CalDAV-compatible server, ensuring you aren’t locked into any single service provider.

Privacy & Security

The core of Etar’s privacy model is the absence of “phone-home” features. There is no telemetry, no crash reporting sent to third-party servers, and zero advertisements. Because the app is open-source, the community can verify that the app only requests the permissions it needs to function—primarily access to your calendar and contacts (to add invitees).

When it comes to security, Etar relies on the underlying Android OS security model. If you choose to sync your data, the security of that data depends on the protocol (CalDAV) and the server you choose. Using Etar with an encrypted Nextcloud instance provides a level of privacy that Google Calendar simply cannot match.

Getting Started

1. Installation: Download Etar from the F-Droid store (the recommended source for privacy) or the Google Play Store.
2. Set Up Storage: Upon opening, Etar will ask for permission to access your calendar. Allow this so it can read and write to the local Android calendar database.
3. Configure Sync (Optional): If you want to sync with a private cloud, install DAVx5 from F-Droid. Add your CalDAV account (e.g., Nextcloud) in DAVx5, and the calendars will automatically appear in Etar.
4. Import Events: If moving from Google, export your calendar as an .ics file from the Google Calendar web interface and open that file on your Android device using Etar to import your history.

Who Is It Best For?

Etar is ideal for:

• Android enthusiasts looking for a “De-Googled” experience.
• Privacy advocates who want to keep their daily schedules off corporate servers.
• Self-hosters who already use Nextcloud, OwnCloud, or similar services.
• Minimalists who want a fast, lightweight calendar app without bloated features or “smart” suggestions.

Final Verdict

Etar is arguably the best open-source calendar app for the Android platform. It manages to balance simplicity with powerful synchronization capabilities. While it requires a bit more setup than Google Calendar if you want cloud syncing (specifically the installation of a CalDAV adapter), the reward is a completely private, tracker-free scheduling tool that you truly own. If you are serious about mobile privacy, Etar should be your default calendar.