---
title: "Calendars over CalDAV"
description: "Keep the calendar of an address in step with Apple Calendar, Thunderbird, DAVx5 on Android and any other CalDAV app, signed in with an app password."
url: "https://openemail.uk/docs/knowledge/addresses/mail-apps/calendars"
area: "Knowledge base"
category: "Mail apps"
---

# Calendars over CalDAV

Keep the calendar of an address in step with Apple Calendar, Thunderbird, DAVx5 on Android and any other CalDAV app, signed in with an app password.

## The settings

A calendar app signs in with the same username and app password as a mail app, and reaches the calendar of that one address.

| Setting | Value |
| --- | --- |
| Server | `api.openemail.uk`, port `443`, HTTPS |
| Full address | `https://api.openemail.uk/dav/`, for apps that ask for a URL |
| Username | The whole address, such as `support@acme.com` |
| Password | An app password for that address, the same kind a mail app uses |

- Calendar apps find the rest by themselves: `/.well-known/caldav` sends them to `/dav/`, and from there to the calendars of the address.
- Seeing the calendar needs permission to read it, and changing events needs permission to change it.
- A password made through a setup link opens the calendar as well as the mail, but never the contacts.
- The calendar can be switched off for one address with its CalDAV switch, in the Servers view of the Mail apps tab.
- Contacts sync the same way over CardDAV, with the same server, username and password.

- [Contacts over CardDAV](https://openemail.uk/docs/knowledge/reading/contacts#contacts-apps): Put the contacts of the workspace into the contacts app of a phone or computer.

## Calendar on iPhone and iPad

1. Open Settings, then Apps, then Calendar, then Calendar Accounts.
2. Tap Add Account, then Other, then Add CalDAV Account.
3. Enter `api.openemail.uk` as Server, the whole address as User Name, the app password as Password and a Description such as Work. Tap Next.
4. Leave Calendars on, turn Reminders off, and tap Save.

- The profile from the Mail apps tab adds the calendar and Mail together, in one step.
- OpenEmail keeps events only, so reminders stay on the device.

## Calendar on a Mac

1. Open Calendar and choose Calendar, then Add Account.
2. Choose Other CalDAV Account, then Continue.
3. Set Account Type to Manual, enter the whole address as User Name, the app password as Password and `api.openemail.uk` as Server Address, and choose Sign In.

> If Manual finds no calendar, choose Advanced instead, with Server Address `api.openemail.uk`, Server Path `/dav/`, Port 443 and Use SSL on.

## Thunderbird

1. Open the Calendar tab and choose New Calendar.
2. Choose On the Network, then Next.
3. Enter the whole address as Username and `https://api.openemail.uk/dav/` as Location, and choose Find Calendars.
4. Sign in with the app password when asked. Thunderbird lists the calendars of the address. Tick the ones you want and choose Subscribe.

## Android, with DAVx5

1. Install DAVx5 from Google Play or F-Droid and open it.
2. Tap the plus button and choose Login with URL and user name.
3. Enter `https://api.openemail.uk/dav/` as Base URL, the whole address as User name and the app password as Password, then tap Login.
4. Keep the whole address as the account name, which DAVx5 uses as the organiser of events you create, and tap Create account.
5. Open the CalDAV tab of the new account and tick the calendars to sync. They then show in Google Calendar and every other calendar app on the phone.

> DAVx5 syncs on the interval set in the settings of the account, and its sync button syncs straight away.

## What the calendar app sees

- A calendar app signed in as an address sees the events that address organises or is invited to, and the events you created yourself. Your subscriptions show beside them as read-only calendars.
- The calendar is called OpenEmail in the app. Each subscription keeps the name you gave it, and renaming one in the app renames it in OpenEmail.
- Events from about three years ago to ten years ahead stay in step. Older and later ones stay in OpenEmail.
- An event can be up to 1 MB. Tasks and reminders are not kept.
- Apps that look up when people are free can see when other addresses of the workspace are busy, up to 120 days at a time.

| For apps that ask | Path |
| --- | --- |
| Discovery | `/.well-known/caldav`, which redirects to `/dav/` |
| Principal | `/dav/principals/{principal}/`, where `{principal}` is the id of the address |
| Calendar home | `/dav/calendars/{principal}/` |
| Events | `/dav/calendars/{principal}/events/` |
| Subscriptions | `/dav/calendars/{principal}/sub-` and the id of each, read-only |

## Invitations and answers

- Inviting people from the calendar app sends real invitations from that address, and answering an invitation there tells the organiser, as the buttons in OpenEmail do. Changing events needs permission to change the calendar, and sending invitations needs permission to send from the address.
- Changing the time, place or details of an event you organised sends the guests an update, and removing a guest sends that guest a cancellation.
- Deleting an event you organised with guests cancels it for all of them. Deleting an invitation you received declines it.

- [Calendar](https://openemail.uk/docs/knowledge/writing/calendar.md): How invitations travel, proposals of new times and sharing the calendar with a link.

## Google Calendar and Outlook

Google Calendar and Outlook.com cannot sign in to another calendar server, so give them a calendar link instead.

## If it does not work

- The app keeps asking for the password: the username must be the whole address and the password an app password for it. OpenEmail answers such a sign-in with Sign in with your email address and an app password from OpenEmail.
- The app signs in but finds no calendar: check that the server is `api.openemail.uk`, not the domain of the address, or enter the full address `https://api.openemail.uk/dav/`.
- This kind of connection is turned off for this address: the CalDAV switch of the address is off. Ask the workspace owner, or someone who manages domains, to turn it on.
- Events cannot be changed: the person whose password it is may only read the calendar, or the event belongs to a subscription.
- Revoking the app password signs the calendar app out within about five minutes.

## Related pages

- [Mail apps](https://openemail.uk/docs/knowledge/addresses/mail-apps.md): The server settings, app passwords, setup links and protocol switches every app needs.
- [Folders, sync and sending](https://openemail.uk/docs/knowledge/addresses/mail-apps/sync.md): How folders, read state, stars and deletions travel between an app and OpenEmail.
- [Troubleshooting mail apps](https://openemail.uk/docs/knowledge/addresses/mail-apps/troubleshooting.md): Every message a mail app can show, what it means and the fix.