Perpetual Calendar

A perpetual calendar can consist of 14 one-year calendars, plus a table to show which one-year calendar is to be used for any given year. One calendar for years starting on a Monday, one for those starting on a Tuesday and so on. Then another seven similar to be used in leap years. And this only works after 1751 when Pope Gregory did his bit with the wayward calendar. Our calendar gadget, is not limited by this - and nor to the usual limit of 50 years like those you can buy elsewhere. Our calendar starts at January 1, 1600, and ends at December 31, 2799. It is based on a repeating cycle of 400 years and a solar cycle of 28 years. It works by means of the "Dominical letter".