Timekeeping
Origin World orbits the M1V stars Groombridge 34A. With a semi-major
axis of about 0.3 AU, it has an orbital period of about 85 Earth days.
It has a rotational period of 20 hours about an axis that is very closely
aligned with the orbital plane, so seasonal variations are minimal.
Thus, an Origin year (of 107 Origin days) is not a fundamental unit of
time.* Instead, Originers count days since the founding
of the first colony on the inferred Earth date of Dec 4, 2087. Thus,
the campaign start date of Earth date Oct 13, 2124 is Origin date 16154,
or (more commonly) OD 154 or the 154th. Thus, the big
"new year" celebrations happen every 1000 Origin days, or about 2-1/4 Earth
years.
* Note that the orbit of Origin World dictates the apparent
motion of the wide-binary companion, Legume, around the Sky. So,
the Origin year is more like a month in the celestial mindset of the inhabitants.