Today is the Equinox, the “equal night” both for the Northern Hemisphere – Vernal or Spring Equinox – and for us in the Southern Hemisphere – Fall or Autumn Equinox.
That day, because of the translation of the Earth around the Sun, plus the Earth’s tilt shift, makes that both hemispheres receive the same amount of light and marks the change between seasons. So, “Only during an equinox is the Earth's 23.5° axis not tilting toward or away from the sun: the perceived center of the Sun’s disk is in the same plane as the Equator”.
These information was crucial for all of our predecessors to make decisions on when to prepare the soil to cultivate, if it was time to harvest, to take specific care of their animals, to go hunting or gathering or to prepare to migrate or not. Basically, the connection to the cycles of the Heavens and the Earth was decisive to know when was a proper time to take certain specific cares of themselves, their families and all Nature for living.
In times where we have access to artificial light during the night, that we can accommodate the weather with air conditioner in our homes, and eat practically everything we want because it’s available at the supermarket, either if it’s something that comes from the other side of the world, we tend to take those things for granted and don’t give much thanks of the interesting time we are living.
And what meant Autumn for previous communities? It was a time for harvest, of collecting the fruits and seeds that Summer had given and prepare themselves for colder and shorter days, that means, to some restrictions, but in a natural solar or annual process of expanding and contracting with Nature.
 Source: https://www.nationalgeographic.org/encyclopedia/equinox/