Date Each Year When Day and Night Are Equal Length

This page is the CodyCross answer for the clue below from Art Museum, Group 726, Puzzle 1 (Online Tickets).

Question is: Date Each Year When Day and Night Are Equal Length

and the answer is: EQUINOX

Word Meaning:

EQUINOX — One of two times in the year (one in March and the other in September) when the length of the day and the night are equal, which occurs when the sun is directly overhead at the equator; this marks the beginning of spring in one hemisphere and autumn in the other.

Definitions from Wiktionary.