September 20 is the 263rd day of the year (264th in leap years) in the Gregorian calendar; 102 days remain until the end of the year. Events Pre-1600. 1058 – Agnes of Poitou and Andrew I of Hungary meet to negotiate about the border territory of …

The September equinox (or southward equinox) is the moment when the Sun appears to cross the celestial equator, heading southward.Due to differences between the calendar year and the tropical year, the September equinox may occur anytime from September 21 to 24.. At the equinox, the Sun as viewed from the equator rises due east and sets due west. Before the …