A calendar is a system of organising days for social, religious, commercial or
administrative purposes. This is done by giving names to periods of time, typically
days, weeks, months and years. A date is the designation of a single, specific day
within such a system. A calendar is also a physical record (often paper) of such a
system. A calendar can also mean a list of planned events, such as a court calendar
or a partly or fully chronological list of documents, such as a calendar of wills.