Sunbird used to be a standalone version of the Thunderbird Lightning plugin, but it is now discontinued. Please see: Sunbird

Also see: https://addons.mozilla.org/en-US/thunderbird/addon/lightning/

The Lightning CalDAV client

Connecting with Lightning

Connecting to a CalDAV server is done through the "File > New calendar" dialog. In this dialog it is possible to specify a CalDAV location.

The URL must be a full URL directly to the actual Calendar.

Implementor notes

User agent