Mystery Calendar Afghan Crochet Along. Calendar ‘Ghan CAL. MATERIALS: The materials are the same each month. You will need a US size “I” hook, and approx 3 - 4 ounces Worsted Weight yarn. The finished size of each square is 12 inches. The finished size of the afghan will be approximately 40 X 54 inches. Winter Dream is the pattern for January 2009.