March 20th is the Vernal Equinox, also known as the first day of Spring.
One of the earliest markers of human civilization is the ability to comprehend & track the cycles of time.
Being able to predict the passage of seasons & celestial events gave people tremendous power to live in tune with the world around them.
All of the earliest monumental structures that survive from ancient times are astronomical markers that helped the priests and leaders of these cultures organize their society.
Synchronizing our lives to the cyclical nature of the universe has been a necessary function for surviving the climatic changes, hunting, agriculture, or social purposes. Because of the importance of seasonal markers, like the equinoxes & solstices, these events were given deep spiritual significance by our ancestors.
These are a couple articles exploring our ancient connection to the occurrence of the equinox.
An ancient solar observatory in Peru.