Showing a Proton calendar on Lantern

Lantern can show a Proton calendar on the wall display and in the app. It subscribes to the calendar’s share link: the events stay in Proton Calendar, where you add and change them, and Lantern shows a read-only copy that it checks every 15 minutes.

Share links need a paid Proton plan, and are made in Proton Calendar on the web, not in the apps.

1. Make a share link and copy it

1. Open Proton Calendar in a browser, then Settings, All settings, Calendars.
2. Choose the calendar you want on Lantern.
3. Under Share with anyone, choose Create link.
4. Choose Full view. A limited view shows only busy times, without titles, so every event on Lantern would read “Untitled”.
5. Optionally give the link a label such as “Lantern”, so you know which link it is later. Then Copy link.

Anyone who has the link can see the calendar’s events, so treat it like a password: Lantern stores it encrypted and never shows it again.

2. Subscribe in Lantern

1. In the Lantern app, open Calendars under Settings in the sidebar (on a phone, open the sidebar with the menu button first).
2. Tap Subscribe to a calendar. Pasting a Proton link chooses Proton Calendar under Where is the calendar?, with these steps beside it.
3. Paste the link, give the calendar a name and a colour, and choose its usual members: the people its events belong to, so they show in their colour and in their column.
4. Tap Subscribe. Lantern checks the link straight away and tells you if it doesn’t work.

The calendar’s events appear at once. Proton says it can take up to eight hours to publish a change through a share link, so an event you add in Proton Calendar may take that long to reach Lantern, however often Lantern checks. Sync now in Settings > Calendars fetches what Proton is publishing at that moment.

If something goes wrong

Settings shows what happened under the calendar’s name:

• “This share link no longer works.” The link was deleted in Proton Calendar (or the calendar was). Create a new link, unsubscribe, and subscribe with the new one.
• “Proton refused that link.” Create a Full view link and use that.
• “Lantern can’t reach that calendar’s server.” Check that the Lantern server can reach the internet.

To stop showing a calendar, open it in Settings > Calendars and tap Unsubscribe, then delete the link in Proton Calendar (Actions > Delete link) so it stops working everywhere.

What Lantern shows

Titles, times, places, and notes, including repeating events and their exceptions. Events from a subscribed calendar can’t be changed in Lantern; change them in Proton Calendar and they update once Proton publishes the change.