If you’re switching from Google Calendar to iCloud, you don’t have to manually re add each event. Here’s how to import your entire Google Calendar to iCloud.
On your Mac, navigate to System Preferences >> Internet and Wireless and click the iCloud icon.
Enter your Apple ID and password to set up iCloud for use with contacts, calendars, and bookmarks.
In the iCloud control panel, make sure Calendars is checked.
Next, open Safari, log into your Google Account and open your calendar. Click the gear icon then select Calendar Settings.
In Calendar Settings click on Calendars.
Next, choose the calendar you’d like to import into iCloud.
Scroll down the page and in the Private Address section, click the green ICAL button.
The Calendar Address screen comes up with a link to your calendar. Click the link to download your calendar.
After the .ics file downloads, double click on it to open iCal.
Select which iCloud calendar to add events to, then click OK. Now your Google Calendar will sync between your Mac and other Apple devices.
Note: If you already have a Google calendar set up in iCal, remove it so events don’t show up twice. To remove it, go back to System Preferences >> Internet & Wireless and click Mail, Contacts & Calendars.
Find the Google account associated with the calendar you just imported to iCloud. Uncheck Calendars.
That’s it! Now you’ll have access to your Google Calendar in iCal and synced to of devices via iCloud. Follow these steps for each Google Calendar you want in iCloud.