Things you need:

• A server supporting WebDAV

Steps when using Lightning

1. Open up Lightning by clicking the Calendar icon in the top-right corner of the Thunderbird window.
2. Click Events and Tasks.
3. Click Publish.
4. Click the calendar you want to publish and click OK.
5. Enter your WebDAV url.
6. Enter a username, password and other required data.
7. You're done!

Exporting a calendar under Thunderbird and Lightning

1. Open the Thunderbird instance.
2. Click Events and Tasks.
3. Use the Export command to open a selection dialog.
4. Select the calendar you want to export and click OK.
5. Specify the file name of the exported calendar, where the exported calendar will be stored. Use the little arrow at the right of the name field to select the appropriate file location.
6. Specify the type of file to create: iCalendar (ICS) format or Web page (HTML) file.
7. Click the Save button.

Using a shared folder

When the calendar file is stored on a shared folder, you may also have several Thunderbird instances opening the same calendar file, provided the proper extension is installed.

Since a standard iCalendar protocol is used, even other calendar supporting products, such as Microsoft Outlook, may share the same calendar.