“Equinox” relates to:
Answer: Period of equal days and night
Equinox relates to period of equal days and night. An equinox occurs twice a year, around 20 March and 22 September. The equinox that occurs close to March 20th is called vernal equinox, In March as the sun is moving northwards along the ecliptic and the equinox that occurs close to September 22nd is called autumnal equinox, In September as the sun is moving southwards. The equinoxes are also the points on the celestial sphere where where the ecliptic and equator cross and the vernal equinox is used as the zero point in measuring star co-ordinates.