equinox
/ˈiːkwɪnɒks/noun
1- the time or date (twice each year) at which the sun crosses the celestial equator, when day and night are of equal length (about 22 September and 20 March)二分点, 二分时刻（指春分或秋分）。
1.1
- another term for EQUINOCTIAL POINT.
词源
late Middle English: from Old French equinoxe or Latin aequinoctium, from aequi- 'equal' + nox, noct- 'night'.