Fall Equinox 2024 Meaning. Occurring around september 22nd or 23rd in the northern hemisphere, it marks the point at which day and night are of equal length before the descent into the shorter days of winter. The first day of autumn often called fall (september equinox or autumnal equinox) is when the sun shines directly on the celestial equator passing from north to south and the length of day and night are almost the same.
In greek mythology, the fall equinox marks the return of the goddess persephone to the underworld for three months, where she is reunited with her husband, hades. The autumnal equinox (as well as spring equinox) is the moment when neither of the earthโs hemispheres is inclined towards or away from the sun.