You can create multiple calendars for any user. However, they are always identified as sub-calendars of the default calendar. The fully qualified name of the new calendar will have the default calendar name on the left of a colon separator and the new calendar's name on the right of the colon separator.
The following example demonstrates how to create another (non-default) calendar for a user, John Smith, with the name of the new calendar as Personal:
cscal -o firstname.lastname@example.org create Personal
The parts of the command are as follows:
The name of the utility.
The unique ID (uid) of the primary owner for this calendar.
The command to create the new calendar.
The second half of the calendar ID (calid) to be assigned to this calendar.
The fully qualified calendar ID is email@example.com:Personal.