23 September को क्यों होते हैं - दिन रात बराबर ? What is September Equinox (Southern Equinox) and the Spring Equinox or Vernal Equinox?

The Equinox (विषुव) occur twice in every year, one on March 20th or 21st and the second on September 22nd or 23rd. 

An equinox occurs when the tilt of the Earth's axis is neither inclined away from nor towards the Sun. This leads to an almost equal duration of the day and the night on Equinox day. 

During March, it is spring time in the Northern hemisphere while it is autumn time in the Southern hemisphere. 

It is spring time in the countries such as 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 spring time in South Hemisphere.

September Equinox is called Autumnal Equinox and Fall Equinox where as it is spring time in the Southern hemisphere and September Equinox is known as Vernal Equinox and Spring 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. 

The Equinoxes are named March Equinox (Northern Equinox) and September Equinox (Southern Equinox) to avoid any kind of confusion.

Vernal Equinox is called Vasant Vishuva or Vasant Sampat in Hindu astrology. Due to precession Hindus celebrate vernal equinox on Mesha Sankranti, according to drikpanchang.