[gmuslera]

A lot of time cycles are rooted on what happens in the sky, not on land, because what happens on land seems to vary all the time, but what happen in the sky seem to be fixed and immutable. The day comes from the Earth rotation. the week and the month originally comes from Moon orbit and phases, the year and seasons from Earth's orbit and tilt.

The seasons in particular happens essentially in the same day in the same way across multiple years. You can put a mark, build a set of monoliths or whatever and see when you are back in that day again, regardless if it is a rainy, cold, hot or windy day. Weather is very variable, and may happen differently in different regions, but you can trust in the skies. And have a clear prediction for that was essential for any civilization based on crops and agriculture, or hunters/gatherers to know when trees will start to bear fruits and some animals come out from hibernation.