Yahren
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Measurement of time
In the original Battlestar Galactica, "yahren" was the Colonial term for "year." Yahren is the same plural as it is singular. See also: Thousand Yahren War.
Note
Within so fan circles, one Yahren is considered to be around 2/3rd the length of an Earth year, thus helping to explain the relative longevity of Colonial people compared to terran humans.