Calendar or iCal (Mac OS X)
1. Download the .ICS file.
2. Go to the file and double-click on it.
3. If a program other than calendar (iCal) opens, return to the file, select it and go to the file menu and select “Open With” then “Calendar” or “iCal.”) Then select your desired calendar or choose to create a new calendar.
2. Then, follow these instructions from Google.
2. Then, follow these instructions from Microsoft.