Thunderbird - use your Google account calendar and contacts
Google account calendar installation
Install the Provider for Google Calendar extension of Philipp Kewisch. This extension allows you to read and write events and tasks on the Google calendar.
After installation, click File -> New -> Calendar. Choose to create the calendar on the network and then select Google Calendar. Follow the rest of the instructions presented to you.
Installing Google account contacts
Install the Josh Geenen gContactSync extension. This extension allows you to synchronize Google contacts with Thunderbird. Synchronization can be bidirectional.
After installing and restarting Thunderbird, the gContactSync wizard appears.
Select your Google account and use your credentials. Before pressing the "Finish" button, review the suggested settings, such as which contacts you want to synchronize (all, just family or other).