Enable multiple calendars on Google Calendar (GMail(CalDAV))

1. Open following URL.

http://www.google.com/calendar/iphoneselect

Google Apps uses can go to https://www.google.com/calendar/hosted/your_domain/iphoneselect (replacing ‘your_domain’ with your actual domain name.)

2. Select the calendars you’d like to sync, and click Save. The selected calendars will display on your device at the time of the next sync.