Proton Calendar: Secure Events

In-app purchases
4.4
6.79K reviews
500K+
Downloads
Content rating
Everyone
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About this app

Proton Calendar is an easy-to-use planner and a time-management tool that keeps your schedule private

Additional Highlights
✓ Schedule planner syncs automatically across browsers and devices
✓ Create recurring events on a daily, weekly, monthly, yearly, or custom basis
✓ Use as an appointment scheduler in local or foreign time zones
✓ Manage up to 20 calendars (paid feature)
✓ View your agenda from the home screen with the Proton Calendar widget
✓ Add multiple reminders for any event
✓ Use as a daily planner or monthly planner by switching between different views
✓ Choose to view your event schedule in dark mode or light mode

PRIVATE CALENDAR
✓ No ads, no trackers, and no data sharing with any third parties
✓ We can’t spy on your activities or misuse your data
✓ End-to-end encryption — fully encrypted data exchange between Proton Calendar users
✓ Zero-access encryption — event names, descriptions, and participants are encrypted on our servers
✓ Based in Switzerland 🇨🇭 — All your data is protected by strict Swiss privacy laws

USERS FIRST
Building an internet that puts people ahead of profits
✓ Funded by users, not advertisers — privacy is our business model
✓ Built by scientists and engineers who met at CERN and MIT and founded Proton Mail
✓ Used by high-profile journalists and organizations globally
✓ GDPR and HIPAA compliant
✓ Based in Switzerland and protected by some of the world’s strongest privacy laws

What others say about Proton Calendar
“Proton Mail has now made it stupid-easy to encrypt your schedule. Information about what you plan to do, where, and with whom, can be just as sensitive as the messages you send and receive.” Gizmodo
Updated on
Mar 9, 2026

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
No data shared with third parties
Learn more about how developers declare sharing
This app may collect these data types
Personal info, Financial info and 5 others
Data is encrypted in transit
You can request that data be deleted

Ratings and reviews

4.4
6.53K reviews
Daniel Stank
March 19, 2026
Extremely slow. I really wanted to like it but creating, updating, or deleting events, especially in a series can take 7-30 seconds, which is slower than anything I work with regularly. If its a series there is a wait for the confirmation to only change one instance and then the regular wait for the action after that. So its not like you can just leave and let it take its time.
Did you find this helpful?
Proton AG
March 20, 2026
That doesn't sound right. Please try clearing the app's data from your device's settings → "Apps" → "Proton Calendar" → "Storage" → "Clear local data/cache" to see if that helps. If the issue persists, submit a bug report via the "Report a problem" feature in the app.
R Dumas
March 18, 2026
Mostly great, except it will randomly log me out. I rely on it to tell me when in get paid so I can pay my bills on time. It's always done this and it's been years. It's losing two stars for that because it's such a critical app that randomly logging users out without notice could be catastrophic (missing critical appointments for you or your loved ones).
Did you find this helpful?
Proton AG
March 19, 2026
That doesn't sound right. Have you noticed any particular actions that might trigger these logouts (app/system update)? Please contact us at https://proton.me/support/contact so we can look into it. In the meantime, try clearing the app's data from your device's settings → "Apps" → "Proton Calendar" → "Storage" → "Clear local data/cache".
Lance English
August 21, 2024
I love what Proton stands for. I've had great experience with their other services. However, the calendar app is not reliable. Events are not reliably syncing from the web app on my PC to the android app. Thus, I'm not receiving notifications and I'm missing important events. I've spoken with support, which was fast and thorough. I hope they get this fixed soon; I want to use this product. Edit: I identified the issue and found a fix.
35 people found this review helpful
Did you find this helpful?
Proton AG
July 15, 2024
Hello Lance! We're sorry to hear about your experience. Could you share your ticket with us here so we can track your case internally and follow-up on your request?

What’s new

Minor fixes and improvements.