Lightening extension allows quick display of current tasks. Task preview pane displaying task parameters like the description, from date, due date, category, etc and calender showing events.

1. Download extension for lightening from this link: https://addons.mozilla.org/en-US/thunderbird/addon/2313
2. Save this file “lightning-0.9-tb-win.xpi” on to your desktop.
3. Open Mozilla Thunderbird, from Tools menu select Add-ons.
4. Click the Install button, and locate/select the file you saved on desktop (lightning-0.9-tb-win.xpi) and click "OK".