- First you need to get your calendar link, the ics URL for your calendar.
- Where do I find my Calendar link for my Caltrics account (webcal ics url)?
- Right-click on the link and select Copy Link Location.
- In Thunderbird, press the Alt key to display the menu bar, then go to File > New > Calendar.
- Select On the Network, and click Next.
- From the Format list, select iCalendar (ICS).
- Right-click in the Address field and choose Paste to enter the calendar location that you copied in step 2, then click Next.
- Give the holiday calendar a name and assign it a color in which all of the holidays are highlighted. Click Next.
- Click Finish.


