Join Date: Aug 2009
Location: Portland, Oregon
I'm not quite sure how'd that work. Usually a planet spins at a regular rate. This means the same percentage is being hit by the sun at any given point, minus any other objects (moons, incredibly large space stations, nearby planets, ect) blocking its light.
There are some planets that one side is in perpetual darkness (There's one in the Ciaphas novels, the Moridan homeworld, and Nostramo).
And of course during Winter, depending on the rotation of the planet, night can last longer than day (look at Alaska, 22 hours of night and 2 hours of light during the Winter). But on the flip side, days get extremely long during the Summer.