Migrating from Sunbird to Lightning

Now that the upcoming release 1.0 of Sunbird, the free standing version of the Mozilla Calendar, has been announced as "the last one ever" (unless, of course, it finds a group of enthusiastic supporters to maintain it, the way the Mozilla Suite did and became SeaMonkey), Sunbird users will sooner or later have to migrate to Lightning (the same Calendar application, but packaged as an "extension" for Thunderbird or SeaMonkey). The aim of this article is to make the transition as painless as possible.

The instructions below are tailored for Thunderbird 3.0 or above and SeaMonkey 2.0.2 or above, which can have tabs in their Mail/News window. For Thunderbird 2, the details will be slightly different. SeaMonkey 1.x users (as well as users of the now obsolete Mozilla and Netscape Suites) are encouraged to migrate to SeaMonkey 2 first.

Before you migrate

Since Sunbird, Thunderbird and SeaMonkey all have different locations for their profiles, you will have to "export" to somewhere on your hard disk any calendar which has been living in your Sunbird profile. This is not hard, you can still use Sunbird (as long as it is supported) after you do it, even use it to change events and/or tasks in the relocated calendar(s), but it is a necessary preliminary step.

Select a calendar in the Calendar tab, then File → Export Calendar

I recommend the ICS format for the "exported" calendars on your hard disk. Repeat this until you have "exported" all the calendars in your profile. (If you are also using remote calendars and/or calendars on your HD but not in your profile, you don't need to export them since they already are at an "application-agnostic" location.)

Installing Lightning

Lightning can be installed in Thunderbird or SeaMonkey from the Lightning homepage. The installation procedure is the same as for any other extension:

• In SeaMonkey, just click the "Install" link, then "Install now" in the popup dialog. Wait until the progress bar is replaced by "Restart SeaMonkey to complete the installation" and restart.
• Since Thunderbird is not a browser, it cannot use the procedure mentioned above. To install Lightning in Thunderbird, save the extension to disk using any browser, then go to "Tools → Addon Manager" in Thunderbird and click "Install" at bottom. Browse to wherever you downloaded the extension, "Open" (or "OK" or whatever) in the file selector, "Install Now", wait, and restart.

Importing your calendars

After you restart the mailer with Lightning installed, click the Calendar button near the right end of the tab bar in the Thunderbird or SeaMonkey 3-pane Mail/News window. This opens a tab whose contents look like your familiar Sunbird. Use File → Open → Calendar... to tell Lightning where your calendars are (on your HD and/or on the net).

If you had been using the "Provider for Google Calendar" extension in Sunbird

The same gdata-provider.xpi can also be used in Thunderbird or SeaMonkey, provided of course that you have Lightning installed. You can install both extensions at the same time so only one restart is necessary.