Track movements of the sun throughout the year, anywhere on Earth. Good for learning how the geometry and motions of the sun and Earth dictate the daily and yearly patterns of day and night or finding specific event details. Can graphically figure: » time of sunrise and sunset » true heading of sunrise/sunset » approximate length of twilight » time of local noon » elevation angle of noon sun. Accuracy of the graphical calculations is about 5 minutes or 5 degrees. Not recommended for the graphically timid. The chart is two sided and measures 10.5 by 13 inches. The two sides are on separate sheets in a clear sleeve. They can be left in the sleeve as a desk reference or can be removed so they can be pinned to the wall.