"Calendars and their History"
an excerpt by L. E. Doggett
A calendar is a system of organizing
units of time for the purpose of reckoning time over extended
periods. By convention, the day is the smallest calendrical unit of
time; the measurement of fractions of a day is classified as
timekeeping. The generality of this definition is due to the
diversity of methods that have been used in creating calendars.
Although some calendars replicate astronomical cycles according to
fixed rules, others are based on abstract, perpetually repeating
cycles of no astronomical significance. Some calendars are regulated
by astronomical observations, some carefully and redundantly
enumerate every unit, and some contain ambiguities and
discontinuities. Some calendars are codified in written laws; others
are transmitted by oral tradition.
The common theme of calendar making is
the desire to organize units of time to satisfy the needs and
preoccupations of society. In addition to serving practical
purposes, the process of organization provides a sense, however
illusory, of understanding and controlling time itself. Thus
calendars serve as a link between mankind and the cosmos. It is
little wonder that calendars have held a sacred status and have
served as a source of social order and cultural identity. Calendars
have provided the basis for planning agricultural, hunting, and
migration cycles, for divination and prognostication, and for
maintaining cycles of religious and civil events. Whatever their
scientific sophistication, calendars must ultimately be judged as
social contracts, not as scientific treatises.