Currently only personal calendars can be managed when the calendar portlet is placed in user personal pages, this means that the user can not display new calendars to Guest or other users through his public or private pages.
Steps to reproduce.
1. As test: add the calendar to one of his public pages, eg, to localhost:8080/web/test
Result: Site calendars menu is not available in the calendar portlet
Expected Site calendars menu is available and the default site calendar is displayed to other users.