Perpetual Calendar

…made from brass in Spain. It’s fun to find out what day of the week was—for instance the first moon landing on 21 July 1969: on the moon side of the device, the vertical row containing 69 intersects with the horizontal row containing 19(hundred) at an “E”. Now it’s turned upside down to see the sun side: combining the “E” with July on top will lead to the calendar on the bottom half—the 21st indicates an “L”, for Spanish Lunes, which is Monday! Apollo 11 landed on the Moon on a Monday.