Event That Marks the Start of Spring or Autumn
This page is the CodyCross answer for the clue below from California, Group 1153, Puzzle 4 (Aerospace Industry).
Question is: Event That Marks the Start of Spring or Autumn
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.