It is finally, officially, the calendar says so AUTUMN!
September 22 marks the Autumn equinox in the northern hemisphere and the spring in the southern hemisphere. Day and night are considered to be near equal in length at the equinox. The term equinox comes from the Latin aequus, which means equal.
Tree
I’ve always wondered… Is it like that on the first day of spring, too?
Equal hours in day and night, i mean
Yes, the first day of spring would be equal daylight and night just like the first day of autumn. The first day of winter is the shortest day of daylight, and the first day of summer is the longest day of daylight.