Every calendar created with create.calendar is stored in the
calendar register.
The idea behind this register is allowing calendars to be accessed
by its names.
Usage
calendars()
remove_calendars(cals)
has_calendars(cals)
Arguments
cals
character vector of calendars names
Details
calendars returns the object which represents the calendars register.
Since the register inherits from environment, the calendars are
retrieved with the [[ operator.
But the register object has its own print generic which helps listing
all registered calendars.
remove_calendars remove calendars from the register.