In astrology, a decan is the subdivision of a sign. In order to give fuller interpretation to the Zodiac Signs, ancient astrologers subdivided each Sign into periods of approximately ten days. These divisions are known as the "decans" or "decantes" and cover modifications of individual traits, attributed to minor planetary influences, which temper or blend with the ruling influence of the period. The ten-day spans are somewhat arbitrary in order to allow for the five (and sometimes six) extra days in the year beyond the 360 days required for the thirty-six decans.
The decans and their rulers are assigned as follows as based on the concepts of ancient Western astrology :
|Sign||1st decan ruler||2nd decan ruler||3rd decan ruler|
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