You can create additional personal calendars below My calendars.
How to create a new personal calendar:
Click the Folder-specific actions icon next to My calendars in the folder view. Click on Add new calendar.
Enter a name. In case the new calendar should be a public calendar, enable Add as public calendar. Click on Add.
User interface:
The Calendar folder view
Related topics:
Subscribing to Google calendars
Subscribing to public and shared calendars
Subscribing to external calendars from an iCal url
Importing calendars from files
Moving appointments to another calendar
Managing Data with Folders
What are folder types?
Parent topic: Adding Calendars