March 20 marks the start of the spring season for the Northern Hemisphere and autumn (fall) in the Southern Hemisphere, with the arrival of the Spring equinox.
Equinoxes – An equinox is a time when the Sun appears directly above the Earth's equator, resulting in roughly equal day and night lengths across the planet.
Equinoxes happen due to the Earth’s axial tilt of approximately 23.5 degrees.
Timing -It occurs twice a year, in the Northern Hemisphere,
The spring equinox, typically occurs between March 19 and 21,
While the autumnal or fall equinox occurs between September 21 and 24.
In the Southern Hemisphere, the March equinox is called the autumnal equinox, and the September equinox is called the vernal equinox.
The March equinox brings later sunrises, earlier sunsets, chillier winds, dryness, and falling leaves in the Southern Hemisphere, while the reverse happens in the Northern Hemisphere.
Cultural Significance
Global -The ancient Babylonian calendar began the 1st full moon following the March equinox, celebrating the new year in the spring.
The Persian new year, Nowruz, coincides with the vernal equinox in the northern hemisphere.
The Vernal Equinox Day is a national holiday in Japan, while Easter (Christianity Festival) is determined according to the vernal equinox.
In the Jewish calendar, Passover, the Jewish festival begins on the 1st full moon following a vernal equinox.
The Rosh Hashanah and Yom Kippur, two of the holiest days of the Jewish calendar, fall in this period.
The autumnal equinox on the other hand sees the observance of autumnal harvest festivals, such as Chuseok, celebrated over 3 days in both Koreas.
In India -The festival of Holi, a vibrant celebration of spring, is often associated with the spring equinox.
Parsis celebrate Nowruz, which is associated with the spring equinox.
Ugadi falls during the spring equinox while Navaratri falls around the time of fall equinox.