what is the date of the autumnal equinox
Equinox An equinox is commonly regarded as the moment in which the plane of Earth's equator passes through the center of the Sun's disk,[2] which occurs twice each year, around 20 March and 23 September. This simplified, but incorrect, understanding of Earth's orbital motion can lead to errors of up to 69 seconds from the actual time of equinox.
Sun path Everywhere around the world during the equinoxes (March 20/21 and September 22/23) except for the poles, the sun rises due east and sets due west. In the Northern Hemisphere, the equinox sun peaks in the southern half (about halfway up from the horizon at mid latitude) of the sky, while in the Southern Hemisphere, that sun peaks in the northern half of the sky. When facing the equator, the sun appears to move from left to right in the Northern Hemisphere and from right to left in the Southern Hemisphere.