For your consideration, here is an AmeriCast Technologies Advertising Plastic 52 Week Calulator Wheel. It is a kind of a cool tool. Given a date and number of weeks, you can calculate the date that week will start on. For example, starting date of September 10th, the date the fifth week starts on is October 15th. The wheel has a little wear on it. The diameter of the wheel is 4 1/4 inches. Item pictured is the actual item up for sale and comes from a non-smoking household. (28.830d-.3ob)