$config_base_url is not set in config.php. Without it there is no hostname to build a subscription link from. Set it to the hostname this install is reached on and reopen this dialog.

Publishing creates a secret link that Google Calendar, Nextcloud, Apple Calendar or Thunderbird can subscribe to.

Anyone with the link can read this calendar without logging in. Share it like a password, and revoke it here if it gets out.

Busy only — publish time blocks without titles, descriptions or locations

Subscription link

Paste this into Google Calendar → Other calendars → From URL, or Nextcloud Calendar → New calendar → New subscription.

Or open directly in a desktop calendar app

> Busy only — publish time blocks without titles, descriptions or locations

Link created
Last fetched

Subscriptions are read-only, and clients decide how often to refresh. Google refreshes on its own schedule (often 12–24 hours) and cannot be forced. Nextcloud defaults to once a week unless calendarSubscriptionRefreshRate is lowered, and refuses subscriptions pointing at a private IP address.