Calendar

Definition

A calendar provides a human interpretation of time. As such, calendars ascribe meaning to temporal values such that the particular meaning or interpretation provided is relevant to its users. In particular, calendars determine the mapping between human-meaningful time values and an underlying time line.

Key Points

Calendars are most often cyclic, allowing human-meaningful time values to be expressed succinctly. For example, dates in the common Gregorian calendar may be expressed in the form <month, day, year> where the month and day fields cycle as time passes.

The concept of calendar defined here subsumes commonly used calendars such as the Gregorian calendar, the Hebrew calendar, and the Lunar calendar, though the given definition is much more general. This usage is consistent with the conventional English meaning of the word.

Dershowitz and Reingold’s book presents complete algorithms for fourteen prominent calendars: the present civil calendar (Gregorian), the recent ISO...