A late 17th/early 18th century German silver circular pocket perpetual calendar, each side with rotating central disc and finely engraved detail, one side inscribed 'Calendarium Perpetuum' above days of the week marked with their planetary signs against days of the month, the other side with month, days of month, tabulation of important saints and feast days, sun's zodiacal position and length of day and night, unmarked, diameter 4.1cm.