Assertion: calendar's year | /r/CapableOf | average out small effect of nutation
Facets:
value: on the equinox
type: TEMPORAL
Source sentences:
text: From the time of Hipparchus and Ptolemy, the year was based on two equinoxes (or two solstices) a number of years apart, to average out both observational errors and periodic variations (caused by the gravitational pull of the planets, and the small effect of nutation on the equinox).