Spring Equinox

An equinox in astronomy is the event when the sun is directly above the Earth’s equator, occurring around the end of March and September each year. More technically, the equinox happens when the sun is at one of two opposite points on the celestial sphere where the celestial equator and ecliptic intersect. In a wider sense, the equinoxes are the two days each year when the center of the sun spends an equal amount of time above and below the horizon at every location on Earth. The word equinox derives from the Latin words aequus (equal) and nox (night). It is celebrated by many cultures around the world in various manners. In many Arab countries, Mother’s Day is celebrated by the March equinox. It also marks the first day of various calendars including the Iranian and Bahá’í calendar and is also a holiday for India, Turkey, Zanzibar and other countries of Central Asia. The calculation of Easter in the Christian church (first Sunday after the first full moon on or after the March equinox), uses its own definition for the equinox – it always falls on March 21. The earliest possible Easter date in any year is therefore March 22.