PlanetOCOs Visibility presents a 3-color graph that shows when a planet, the moon or the sun is visible during any year from 3000 BC to AD 6000 at any location on the earth. The vertical axis marks the months of the year, the horizontal axis marks the hours of the day. The three colors create a contour map effect and show whether the body is under the horizon and invisible, above the horizon with the sun and invisible, above the horizon.