When Is The 1st Day Of Fall 2024 Calendar. Review instructions for downloading the academic calendar. That's the day of the autumnal equinox when day and night are nearly equal in length.
That’s the day of the autumnal equinox when day and night are nearly equal in length. In 2024, the autumnal (fall) equinox arrives on sunday, september 22, marking the official first day of fall.