noun
Any system by which time is divided into days, weeks, months, and years.
A means to determine the date consisting of a document containing dates and other temporal information.
A list of planned events.
An orderly list or enumeration of persons, things, or events; a schedule.
(US) An appointment book (US), appointment diary (UK)
verb
(law, transitive) To set a date for a proceeding in court, usually done by a judge at a calendar call.
(transitive) To enter or write in a calendar; to register.