Calendar with removable pins. (Saturn, Sun, Luna, Mars, Mercury, Jupiter, Venus) From the stone plate of the 3rd—4th cent, CE, found in Rome. The first pin designated the day of week: it was inserted into the hole under the image of the god-protector of the day (the row begins with Saturn, from left to right, cf. the picture; Sun, Luna, Mars, Mercury, Jupiter, Venus following next).