Using the current version.
Goto:
Control Panel » Portal Layout
Public Calendar
Elect where you want it to display.
Right,left and position.
Second step.
Goto:
Control Panel » Site Permissions
Select Can create new calendar events
Add a 1 to what group you wish to allow post entries.
the cache option just sets how often to update the calendar.
Oh,
Note: The Private Calendar is not available outside of the portal. This is different than a public calendar-feature wise.
Is just that, the private calendar is a feature that say I can create my own personal calendar and nobody else has access to it.
I don't know why anyone would use it though.
Last edited by Ruben; 06/16/2013 4:31 PM. Reason: Added Comment.