First Day Of Fall 2025. All observances except passover begin the prior evening. 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.

This year the autumn will start on sunday september 22, 2024 (day of the fall equinox) and will end on saturday december 21, 2024 with the winter solstice. There, the date of the autumnal equinox can change between march 19 and 21.