Ok, so, how do you sync your Google Calendar with Thunderbird Mail Client so that you have it all on your desktop?
Install what you need
1. Install Thunderbird
2. Install Lightening (It will also install Google Provider which you will see in your Thunderbird Addons)
Open your Google calendar online in Firefox
3. Login to your Google Calendar and look down to the left and you will see a pink box with your calendar name, and just below it says “settings”.
4. Click Settings and you will get the Calendar Settings page where you need to click the second “Calendars” tab.
5. Now click on your calendar below (It’ll most likely say “firstname.lastname@example.org”)
6. You are now at “Calendar Details”, scroll down to your private address and click it.
7. A box will open with a link like this: (yup, I edited it with 1’s and X’s)
8. Right Click and copy that link.
9. Open Thunderbird and choose Calendar.
10. Now click the Calendar tab, choose “New Calendar”, “On The Network”, “Google Calendar”.
11. Paste your private link that you just copied into the location box and then just go through the process and add your password.
All done! Now you will see all of your Google Calendar links appear in Thunderbird.