Semi-annual astronomical event where the Sun is directly above the Earth's equator A solar equinox is a moment in time when the Sun appears directly above the equator, rather than to its north or south. On the day of the equinox, the Sun rises almost exactly in the east and sets almost exactly in the west. This occurs twice each year, around 20 March and 23 September. 215,139 views on March 20, 2016 — Wikipedia's most-read article that day. Also most read: Troubadour, Donald Trump, UFC Fight Night: Hunt vs. Mir, Punisher. Wiki link