2017 Autumnal Equinox, March Equinox

An Equinox is an astronomical event that happens twice, once in spring and once in autumn, each year when the tilt of the Earth’s axis is inclined neither away from nor towards the Sun. During Equinoxes the tilt of the Earth (with respect to the Sun) is 0° and because of it duration of the day and the night are almost equal on Equinox day i.e. 12 hours.

Equinoxes occur on 20th or 21st March and 22nd or 23rd September each year and both days has equal length of the day and the night.

During March it is spring time in the Northern hemisphere and March Equinox is called Vernal Equinox and Spring Equinox while it is autumn time in the Southern hemisphere and March Equinox is called Autumnal Equinox and Fall Equinox. In other words on March Equinox it is spring time in the UK, the USA, Canada, Russia, India and China while it is autumn time in Australia, Argentina, Chile, New Zealand and South Africa.

Similarly, during September it is autumn time in the Northern hemisphere and September Equinox is called Autumnal Equinox and Fall Equinox while it is spring time in the Southern hemisphere and September Equinox is called Vernal Equinox and Spring Equinox. In other words on September Equinox it is autumn time in the UK, the USA, Canada, Russia, India and China while it is spring time in Australia, Argentina, Chile, New Zealand and South Africa.

To avoid any confusion Equinoxes are preferably referred as March Equinox (Northern Equinox) and September Equinox (Southern Equinox).