Connect a CalDAV Calendar or Add an ICS Calendar Feed

Connect a CalDAV calendar (Fastmail, Nextcloud, Zoho) or add a read-only ICS feed (Outlook, Proton) from Integrations → Calendars. Every plan can use both.

Overview

Besides Google, Microsoft 365 and Apple (iCloud), TidyCal can check two more kinds of calendar for conflicts, so people booking with you never see a time when you are busy:

Both are available on every plan, including the Free Plan. A CalDAV calendar or a feed counts toward your calendar limit like any other calendar: the Free Plan can check 1 calendar for conflicts. See the limits table in Which Apps and Calendars Does TidyCal Integrate With?.

Go to Integrations → Calendars. The page has five buttons: Add Google account, Add Microsoft 365 account, Add Apple account, Add other calendar (CalDAV) and Add calendar feed (ICS). For Google, Microsoft and Apple, see Adding Calendars to your TidyCal account.

Connect a CalDAV Calendar

Before you start: create an app password in your provider's security settings and use it instead of your main password. Look for "app passwords" or "app-specific passwords". The exact steps depend on your provider, so follow its own help pages.

1. Go to Integrations → Calendars and click Add other calendar (CalDAV).
2. Choose your Provider: Fastmail, Nextcloud, Zoho, kSuite (Infomaniak), mailbox.org or Custom. Choosing one fills in the Server address for you. For Nextcloud, enter https://your-host/remote.php/dav with your own host name. For Custom, enter the public https address of your CalDAV server.
3. Enter your Username and your App password.
4. Click Add account. TidyCal checks the details before it saves them.
5. TidyCal lists your calendars under Connected accounts. Switch on Reading enabled for each calendar whose events should block your availability. New CalDAV calendars start with reading off, except the first calendar if you have no Primary calendar yet, which becomes your Primary calendar.

To have new bookings written to a CalDAV calendar, click Set primary on it.

Good to know:

• You cannot change the server later. To use a different server, disconnect the account and connect again.
• You can connect up to 10 Apple and CalDAV accounts in total, because iCloud counts toward the same limit.
• Events marked as free (transparent) do not block your availability. Other events do.
• TidyCal checks CalDAV calendars the same way it checks iCloud: regularly in the background, and again when you or someone on your booking page triggers a check. If a change is missing, use Resync on the calendar's events page. See Why aren't my calendar events blocking my availability in TidyCal?.

Add an ICS Calendar Feed

Use a feed when a calendar offers no CalDAV access but can be shared as a link. In your calendar app, look for an option to publish or share the calendar as an ICS or webcal link; the wording is different in every app. Copy the link.

1. Go to Integrations → Calendars and click Add calendar feed (ICS).
2. In Feed link, paste the ICS or webcal:// link.
3. Optionally enter a Name, such as Work calendar.
4. Click Add feed. TidyCal reads the feed before it saves it.

Reading is switched on straight away. The feed appears under Connected accounts as Read-only feed with its last sync time, and its calendar is marked Conflicts only.

Good to know:

• TidyCal checks the feed for conflicts about every 15 minutes. It also checks when you or a booker use TidyCal, but not more than every 5 minutes.
• A feed can never be your Primary calendar and never receives bookings. It shows View-only instead of Set primary. Keep a Google, Microsoft, Apple or CalDAV calendar as your Primary calendar.
• Busy events block your availability, including recurring events (TidyCal looks about six months ahead) and tentative events. Events marked as free (transparent) and cancelled events are skipped. All-day events block unless the source calendar marks them as free.
• The link is private. Anyone who has it can read the calendar, so do not share it.
• Very large feeds can be refused.
• To stop using a feed, click Remove on it.

Keep Your Calendars Connected

If a CalDAV account needs to reconnect

If you change or revoke the app password, TidyCal can no longer read the calendar. You will see a Please Reconnect button, and a banner that says the calendar is disconnected, with the CalDAV server address shown in place of a provider name (for example caldav.fastmail.com). New bookings are not added to it, and TidyCal cannot see when you are busy there. TidyCal may also email you reminders.

Click Please Reconnect to open Update calendar account, enter the new App password and click Update account. If the account stays disconnected for 30 days, TidyCal stops reading it.

If a feed stops refreshing

If a feed cannot be refreshed, its card shows Couldn't refresh with a reason. After three failed attempts in a row TidyCal emails you. Busy times from the last good refresh keep blocking, so you are not double-booked in the meantime. Check that the feed link still works, because some calendar apps change it when you re-share a calendar. To use a new link, remove the feed and add it again.

Troubleshooting

I cannot add my CalDAV account

• "The server rejected this username or app password": check your username and use an app password, not your main password.
• "This server address is not a public host" or "The CalDAV server must be a public https:// address": use the public https address of your CalDAV server, not a local or private address.
• "We couldn't reach this CalDAV server": check the server address and try again.
• "You can connect up to 10 Apple or CalDAV accounts": disconnect one to add another.

I cannot add my feed

• "The feed link must be a public https:// or webcal:// address": paste the full link from your calendar app.
• "You've already added this calendar feed": the feed is already in your list.
• "We couldn't read that feed": the message adds a reason, such as the link no longer being shared, the feed's server having a problem, or the link not returning a valid calendar (.ics) file. Check the link in your calendar app and copy it again.

My events are not blocking my availability

• Check that the calendar shows Reading enabled. New CalDAV calendars start with reading off.
• If TidyCal says you have reached your limit of calendars checked for conflicts, turn off reading on another calendar first, or upgrade to check more.
• Events marked as free do not block. See Why aren't my calendar events blocking my availability in TidyCal? and Outlook, iCloud or Google Workspace Calendar Not Syncing?.

Still stuck? Email support@tidycal.com (see How do I contact TidyCal support?).

Frequently Asked Questions

Which plans can connect CalDAV calendars and ICS feeds?

Every plan, including the Free Plan. How many calendars TidyCal checks for conflicts is set by your plan: 1 on the Free Plan, 10 on Individual Lifetime, 10 on Agency Lifetime (25 if purchased before September 1, 2026) and unlimited on Pro. Only calendars and feeds with Reading enabled count.

Can I connect Proton Calendar?

Yes, as a calendar feed. Use your Proton calendar's share link in Add calendar feed (ICS). TidyCal then sees when you are busy in Proton, but a feed is read-only, so bookings are not added to your Proton calendar. Choose a Google, Microsoft, Apple or CalDAV calendar as your Primary calendar for new bookings.

Will my bookings appear in my CalDAV calendar or feed?

On a CalDAV calendar, yes, once you set a writable calendar as your Primary calendar. On an ICS feed, no. A feed is only used to check for conflicts.

Should I use CalDAV or an ICS feed?

Use CalDAV if your provider supports it, because it can also receive your bookings. Use an ICS feed if the calendar can only be shared as a link.

Related Articles

• Adding Calendars to your TidyCal account
• Why aren't my calendar events blocking my availability in TidyCal?
• Outlook, iCloud or Google Workspace Calendar Not Syncing?