Organize your schedule and life's important events in a calendar that's fully integrated with your Thunderbird email. Manage multiple calendars, create your daily to do list, invite friends to events, and subscribe to public calendars.
- Go to the link above for your operating system and follow the instructions on the addons.mozilla.org website.
- In Thunderbird, open the extension manager in the Tools/Add-ons menu
- Click the Install button, and locate, select the file you downloaded and click "OK"
- Close and reopen Thunderbird to finish the install
Alternatively, you can use the addons manager from inside Thunderbird to install Lightning.
The first time you run Thunderbird after installing Lightning, be sure to go to the Lightning pane in the Preferences or Options dialog and manually set your timezone correctly, and then restart Thunderbird once more. This will prevent your events from being created in wrong timezone.