Start Of The Seasons -

There is a specific kind of magic in the air when one season bows out and another takes the stage. It happens four times a year, yet it never ceases to feel like a small miracle.

These occur halfway between the solstices when the sun's path aligns directly with the Earth's equator. On these days, nearly every location on Earth experiences roughly 12 hours of daylight and 12 hours of darkness. Why Do We Have Seasons? - National Weather Service start of the seasons