Install xul-ext-lightning by entering the following commands in the terminal:
sudo apt update sudo apt install xul-ext-lightning
Description:
Calendar Extension for Thunderbird
Lighting is the Mozilla Calendar extension for Thunderbird, based on Sunbird - the Mozilla Standalone Calendar application. It is tightly integrated with Thunderbird, allowing it to easily perform email-related calendaring tasks.
Version: 1:52.7.0+build1-0ubuntu1
Section: universe/web