Question

When do the world observe equinoxes​

Answer 1

Answer:

The equinoxes happen in March (about March 21) and September (about September 23). These are the days when the Sun is exactly above the Equator, which makes day and night of equal length.

These are known as the equinoxes: the autumnal equinox and vernal or spring equinox. It's the moment at which the plane of Earth's equator passes through the centre of the Sun's disk, or the moment that the Sun passes the celestial equator. On these dates, there are approximately equal hours of daylight and darkness.

An equinox is commonly regarded as the instant of time when the plane (extended indefinitely in all directions) of Earth's equator passes through the geometric center of the Sun's disk. This occurs twice each year, around 20 March and 23 September.

Answer 2

On Earth, there are two equinoxes every year: one around March 21 and another around September 22. Sometimes, the equinoxes are nicknamed the “vernal equinox” (spring equinox) and the “autumnal equinox” (fall equinox), although these have different dates in the Northern and Southern Hemispheres.