First, create a new calendar at Google:
Click the gear icon in the top right to go to your calendar settings:
Expand the "Add a calendar" section and choose to create a new calendar:
This is the name it will sync in to 17hats with:
You'll know it worked if see it in the My Calendars list at Google:
Back at 17hats, go to your Calendar Settings page and click "Google Cal Settings", then choose "Update Calendars to Sync":
You'll see the new calendar - check the box and click the green "Save" button to begin syncing your new Google Calendars with 17hats: