Open Source Google Calendar Alternative

3 Open Source Google Calendar Alternatives for Android: Our Best Picks

If you’re an Android user and a fan of open-source software, you’ve probably found yourself looking for an open source Google Calendar alternative at some point. While Google’s offering is robust and widely used, it’s not open source, and some users prefer software that is. Today, we’re going to look at three open-source alternatives to Google Calendar for Android: Etar, Proton Calendar, and Simple Calendar Pro.

Etar: A Clean and Minimalist Open Source Google Calendar Alternative

Etar Calendar

First on our list is Etar, an open-source calendar that is both clean and minimalist. Etar is built on the same foundation as the AOSP (Android Open Source Project) Calendar, which means it has a familiar interface for those used to Google’s Calendar app.

Etar offers a day, week, month, and agenda view, just like Google Calendar. It also supports syncing with Google Calendar, so you don’t have to worry about losing any of your events. Etar is a great choice for anyone looking for a simple, open source Google Calendar alternative.

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Proton Calendar: Privacy-Focused Open-Source Calendar

proton calendar

Next up is Proton Calendar, a product from the same team that brought you ProtonMail. Proton Calendar is a privacy-focused, open-source calendar app that encrypts your event data before it reaches their servers.

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Proton Calendar offers a clean, easy-to-use interface, and like Etar, it provides day, week, and month views. One of the standout features of Proton Calendar is its emphasis on privacy, making it an excellent choice for those who want to keep their schedule private and secure.

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Simple Calendar Pro: A Versatile Open-Source Calendar

Simple Calendar Pro

Last but not least is Simple Calendar Pro, a versatile, open-source calendar app that is part of the Simple Mobile Tools suite. Simple Calendar Pro supports syncing with Google Calendar and other online calendar services, making it a flexible option for those who use multiple calendar platforms.

Simple Calendar Pro offers a variety of views, including an events list and a yearly view, in addition to the standard day, week, and month views. It also includes a search function, a rarity among open-source calendar apps.


Whether you’re looking for a minimalist design, a privacy-focused platform, or a versatile tool, there’s an open-source Google Calendar alternative for you. Etar, Proton Calendar, and Simple Calendar Pro each offer unique features that make them worthy alternatives to Google’s popular calendar app. Give them a try and see which one fits your needs the best.