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. According to accepted prodcedure, these days have thus been added to form various six-day periods instead of five. The earliest records of decans have been found inside coffin lids dating from the Tenth Egyptian Dynasty around 2100 B.C. Decans are also mentioned in the Babylonian Enuma Anu Enil, which dates approximately four centuries later. The root of the word “decante” is Greek in origin and means “ten days apart.”
The planetary influences described under the decans are valuable in “shading” the traits of many individuals, but are generally subordinate to the stronger characteristics associated with the primary Zodiac Sign. In some people, the traits of the decans may only be slightly traced…in others, they are very marked. As a general rule, the primary Sign of an individual details his or her characteristics with what can be surprising exactitude, but where such individual traits may seem at variance with the accepted patterns of the Sign, then the answer may be found in that person’s decan. A study of the decans may also reveal hidden factor’s to which a person may be susceptible, even though his or her major traits are fully delineated under his or her primary sign.
Source: http://www.novareinna.com/constellation/
