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Dictionary definition: calendar
- Article from:
- A Dictionary of World History
Copyright© A Dictionary of World History 2000, originally published by Oxford University Press 2000. (Hide copyright information)
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calendar
Any system for fixing the beginning, length, order, and subdivisions of the year. Calendrical systems have been used by societies since the earliest times, nearly all of them based on one of two astronomical cycles: the cycle of the phases of the Moon (the synodic month or lunation), often of major ritual and religious significance, and the cycle of the seasons (the period of the Earth's orbit around the Sun), of importance in agriculture. The two cycles are incompatible in that the synodic month has a period of about 29.5 days, giving a lunar year (12 months) of just over 354 days, over 11 days shorter than the mean solar year of 365.2422 days.
The
Julian calendar
was introduced to ...