September 22 is the Autumn Equinox. Why isn’t it the Autumn Solstice ?
An equinox is when day and night are roughly equal in length, marking the start of spring and autumn. A solstice is when one hemisphere experiences its longest day (summer solstice) or shortest day (winter solstice), marking the start of summer and winter. The key difference is that equinoxes balance daylight and darkness, while solstices represent the extremes of light and dark
It falls between September 21 and 24, with the specific date varying slightly year to year due to Earth’s orbit. This year it is Mon., Sept 22 at 2:19PM. In our hemisphere, sunlight will gradually diminish each day until the winter solstice on Dec. 21.
Here is a video on this important distinction: