Calendar with frame and annual card - incorporates table for four hundred years with datum numbers

摘要

The calendar comprises a frame in which a calendar card for the year fits. On the frame is an indication of the weekdays and of the respective year, while on its front or rear or on the rear of the card or the cassette containing it is a table of four hundred successive years, with the respective datum numbers for annual calendars numbered 1 to 14. The 14 calendars can be on separate cards, or on the front and rear sides of seven cards. Each card can have the normal calendar on the front and the leap year one on the back which begins with the same weekday.