A Data::ICal object represents a VCALENDAR object as defined in the iCalendar
protocol (RFC 2445, MIME type "text/calendar"), as implemented in many popular
calendaring programs such as Apple's iCal.

Each Data::ICal object is a collection of "entries", which are objects of a
subclass of Data::ICal::Entry. The types of entries defined by iCalendar (which
refers to them as "components") include events, to-do items, journal entries,
free/busy time indicators, and time zone descriptors; in addition, events and
to-do items can contain alarm entries. (Currently, Data::ICal only implements
to-do items and events.)

Data::ICal is a subclass of Data::ICal::Entry; see its manpage for more methods
applicable to Data::ICal.