A yahren is a Colonial measurement of time.
Analagous to an Earth year; plural form is same as singular, "yahren".
Note[edit]
Within some fan circles, a yahren is considered to be around two-thirds (2/3) the length of an Earth year, thus helping to explain the relative longevity of Colonial people compared to Terran humans. This reasoning is picked up in Richard Hatch's sequel novels. The glossary in the first novel Armaggedon states that a yahren is 200 days.
In the reimagined series the colonials say year instead, although a brief mention of the term appears in the documents visible at Armistice Station.
See also: Thousand Yahren War
See also: Units of Measure (TOS)