Locating occluded (shaded or unshaded) areas of a topography using Grasshopper

I want to be able to use Grasshopper to determine where occluded (shaded) or un-occluded (un-shaded) areas of any given terrain are located.

The idea is to run a sun study to determine which areas receive the most or least amount of light throughout the day.

Do you know how I could "filter" out test points that receive an undesirable # of sunlight hours in order to obtain a list of the locations and their respective # of sunlight hours?

For example: If I wanted to see only the locations that have 5 or more daylight hours in any given period of time.

Two approaches to this problem have been taken so far, and I have attached both files.