Describe the length of the day during winter, spring, summer, and fall.

In the summer the northern hemispher gets the most light and the further north you go or the higher latitude the more daylight you get. The Equator is more half and half. The north pole, the sun never sets. 
Winter the further north you go, the more night time you get. Equator is still more or less half and half.

Probably a behavioral adaptation