Exactly WhiteRabbit.
The equinoxes and solstices are actually the middle of the periods of seasonal weather changes. So while the western world (and a lot of the rest of the world now following suit) have them at the beginning of each season, other parts of the world have traditionally used them at the center of each season.
The middle of each season makes sense to me. The middle of the summer season would then be the longest day and the middle of the winter season would then be the shortest day.
Anyway, we use what we use and that's the way it is and I
really don't want to think that it's now autum, otherwise it's been a
really short summer!