Here a short description how to setup google calendar on your iPhone. This setup doe not require to sync. Booth, google calendar and the iphone update each other instantly.
1. Go to Settings / Mail, Contacts, Calendars

2. Click on “Add Account”

3. Select “Microsoft Exchange”

4. Add the details using your email address and your password

5. it Currently only works for Contacts and Calendars. NO EMAILS!
Caution: if you want to also sync Contacts, make sure that you don’t have any phone numbers in Gmail saved as “other” this numbers will not show up until you change it to “Home, Mobile or Work”

6. Got to m.google.com/sync with your iphone browser. Make sure you are viewing the Website in English, otherwise it will tell you that the device is not supported.

7. Change to English

8. if all goes well, you will see your iphone listed. Click on it and select all the Calendars you wish to see on the
iPhone.

Enjoy


