DCalendar: Private Calendar

DCalendar is a calendar that keeps the details of your plans to yourself. Every event body is encrypted on your phone before it is sent anywhere, under a key only your NCOG Wallet can unwrap. There is no password to set, and none for anyone to steal.

It is also a calendar you can run your week from: Day, Week, Month and Schedule views, tasks that tick off, repeating events, all-day events, and a real Google Meet or Zoom link on the events that need one. Swipe between periods, jump to a date, or search titles, locations and guests.

You need the NCOG Wallet app

Signing in opens NCOG Wallet and asks you to approve. The wallet holds your keys, which is what makes the passwordless sign-in and the encryption work: it unwraps the key to your calendar and signs every event you save. Install it first, or DCalendar cannot get past the sign-in screen.

Events, tasks and time off

- All-day events, and a timezone per event from 77 major zones
- Repeats: daily, weekly, chosen weekdays, fortnightly, monthly, monthly on the nth or last weekday, yearly, weekdays only, or a custom every-N rule
- Invite guests by email or straight from your dContacts address book. They get a standard .ics attachment that opens in any calendar. Repeating events are invited one date at a time
- Tasks with their own dates, times and repeat rules, ticked off in one tap
- Out of office entries for the days you are away, shown on your own calendar
- A recycle bin: restore one, restore all, or delete for good

Google Meet and Zoom

Connect a Google or Zoom account in Settings, then choose Meet or Zoom on an event: DCalendar creates the real meeting, updates it when you move the event and cancels it when you delete. Meet needs Google Play services. Google Meet and Zoom are trademarks of their owners; DCalendar is not affiliated with either.

What is encrypted, and what is not

The body of every event is encrypted on your phone before it is sent anywhere: description, location, guest list, meeting link, repeat rule and timezone. The key is a data key of your own, sealed to your ML-KEM public key. NCOG's server only ever holds it sealed; it is unwrapped inside your NCOG Wallet, and DCalendar keeps the unwrapped copy in memory rather than writing it to storage. A decrypted copy of your calendar is cached on the device so it opens instantly.

Sign-in is an ML-DSA-87 signature over a single-use challenge. ML-KEM and ML-DSA are post-quantum algorithms standardized by NIST.

Not encrypted: the event title, its start and end times, its id and invitee email addresses. Those go to the NCOG blockchain, signed by your own wallet, as a permanent public record - anyone who knows your NCOG username can read them. Times and repeat rules also reach the NCOG server in the clear. Invitations are ordinary email with a plain .ics attachment, readable by our relay and by any mail server it passes through. If a title would be sensitive on a permanent public record, put the detail in the description instead.

Nothing to lock you in

Import an .ics file from another calendar. Duplicates are skipped and you are told what came in. Export your events from Settings whenever you like.

What DCalendar does not do yet

- No push notifications. You can set a reminder lead time on an event, but this version will not buzz your phone
- No year view. Day, Week, Month and Schedule only
- No shared or subscribed calendars, and no RSVP tracking
- No file attachments and no dark mode
- A repeating event is edited and deleted as a whole series
- Your last loaded calendar shows offline, but creating and editing need a connection and a wallet approval

One suite, one wallet

DSuite is dMail, dChat, dContacts, DCalendar and dForms, all from NCOG and all signed into with the same wallet. DCalendar reads the address book you keep in dContacts, so the people you invite are already there.

Requires the NCOG Wallet app. ncog.earth