theres this map chart thing?

Question

theres this map chart thing at my library its iluminated and it has the sun light hours, its hard to explain but where ever the light is on the map that meens the sun is up in that area if the other area is dark its nightime in the area what are these things called

Answer 1

It's called a geochron.

Answer 2

At least one set of them are called "Geochron". Check here:

http://www.maps.com/Maps.aspx?cid=7,70&nav=MS