The September Equinox occurs around September 22 or 23 each year, marking the moment when the sun crosses the celestial equator. This event results in nearly equal day and night lengths across the globe. It signifies the start of autumn in the Northern Hemisphere and spring in the Southern Hemisphere. During the equinox, the sun rises due east and sets due west for most locations on Earth. This phenomenon is part of the Earth's tilt and orbit around the sun, which also influences seasonal changes. The September Equinox is one of two equinoxes each year, the other being the March Equinox.