Private Calendar

Private Calendar is a calendar for appointments, tasks, and reminders whose contents only leave your device encrypted.

Everything you enter is encrypted on your device with AES-256-GCM before being synchronized. The server stores calendar content exclusively as unreadable blocks. Without your key, it remains unreadable—for everyone.

A COMPLETE CALENDAR

• Month, week, day, and appointment list, with swipe and zoom functionality in a time grid
• Drag appointments to move them, adjust durations directly
• Recurring events from daily to yearly, plus an editor for special cases
• Tasks with a completed checkmark for each occurrence
• Multiple calendars with custom colors, German holidays, and time zones

• Full-text search across the entire history; the search index remains encrypted on your device

• Light and dark themes, import and export as JSON or iCalendar

• Background synchronization The same appointments are available in your browser.

ENCRYPTION YOU CAN VERIFY

• Your key is generated from your password and remains with you. Calendar and master keys only reach the server encrypted.

• Technical data such as email address, sharing partners, and modification timestamps are not encrypted.

• The encryption source code, the complete specification, and a tool for decrypting data exports without our software are publicly available.

• Two-factor authentication (TOTP) is a standard feature of the account.

• App lock with fingerprint or face unlock: This protects the content displayed on this device. It does not replace account login and does not re-encrypt the local database.

SHARING AND SUBSCRIBING (Premium)

• Share your own calendars with end-to-end encryption – using a security code that both parties compare via a separate channel.

• Booking links: Share available time slots without requiring the other person to have an account.

• Subscribe to external iCal calendars. The Android app retrieves the link directly from the source; the Private Calendar server does not receive the link or the content in plain text. The source sees your device's IP address or network. Updates occur at most every six hours and only if Android allows background processes. Link subscriptions cannot be updated without a logged-in Android device.

WHERE YOUR DATA IS STORED
The servers are located in Germany, subject to European data protection regulations. In addition, there is an exclusively encrypted offsite backup in Switzerland. However, data recovery is not guaranteed – exporting your own data is still recommended.

PLANS
Free: 2 personal calendars, 25 MB storage, appointments, tasks, reminders, and export – permanently, without a time limit.

Premium: Up to 25 personal calendars, 500 MB storage, sharing, iCal subscriptions, booking links, multiple scheduled reminders, and task deadlines. Premium is included with the Private Calendar account; the app itself does not contain any purchase option.

IMPORTANT REMINDERS

Android, power saving rules, Doze, and app sleep mode can delay or suppress notifications. Never rely solely on these for critical deadlines.

An account with an email address and password is required. Android 8 and later. No ads, no tracking.