Autumn Equinox 2024 Date. When do the four seasons start in 2024—for spring, summer, fall, and winter? Autumnal equinox, two moments in the year when the sun is exactly above the equator and day and night are of equal length;
Cdt) and will last until the winter solstice on saturday,. On these days, everywhere on earth experiences roughly 12 hours of sunshine and 12 hours of darkness.