what date is the autumn equinox

The autumnal equinox occurs when the Sun crosses the celestial equator going south, and it is the moment when day and night are of equal length. According to the astronomical definition of the seasons, the autumnal equinox marks the beginning of autumn, which lasts until the winter solstice. In the Northern Hemisphere, the autumnal equinox falls about September 22 or 23. In 2023, the fall equinox and the first day of autumn will arrive on Saturday, September 23, at 02:50 A.M. EDT in the Northern Hemisphere. The Royal Museums Greenwich also confirms that the autumnal equinox will occur on September 23, 2023, at 6:50 am GMT (7:50 am BST) .