HEGone of the two times in a year when night and day are of equallength 二分时刻,昼夜平分时〔指春分或秋分〕 → solstice
the spring equinox
春分
Examples from the Corpus
equinox• There arc four seasons, or rather four solar points of the year, the solstices and equinoxes.• Only during the time of the spring and autumnequinoxes do our aquariums have a tropical day.• Dominic knows that in the 1960s the equinox had progressed to Aquarius.• The equinox had surely passed already, and perhaps the solstice was approaching.
Originequinox
(1300-1400)Frenchéquinoxe, from Latinaequinoctium, from aequi- (EQUI-) + nox“night”