Follow these steps: (using a web browser)
- Click the down-arrow next to Other calendars.
- Select Add by URL from the menu.
- Copy and paste this address into the field provided:
- Click Add calendar. The calendar will appear in the Other calendars section of the calendar list to the left.
- Note: It may take up to 8 hours for changes in ICS feeds to reflect in your Google Calendar.
Directions from google