A perpetual calendar is a calendar which is good for a span of many years, such as the Runic calendar. A calendar is a system for naming periods of time, typically days. ... The Runic calendar (or Rune staff) appears to have been a medieval Swedish invention, whereas clog almanacs appear in several European countries. ...

For the Gregorian calendar, a perpetual calendar often consists of 14 one-year calendars, plus a table to show which one-year calendar is to be used for any given year. Note that such a perpetual calendar fails to indicate the dates of moveable feasts such as Easter. The Gregorian calendar is the calendar widely used in the Western world. ... In Christianity, a moveable feast or movable feast is a holy day -- a feast or a fast -- whose date is not fixed to a particular day of the calendar year but moves in response to the date of Easter, which date varies according to a complex formula. ... Easter is the most important religious holiday of the Christian liturgical year, observed in March, April, or May to celebrate the resurrection of Jesus from the dead after his death by crucifixion (see Good Friday), which Christians believe happened at about this time of year around AD 30-33. ...

The Perpetual Calendar has 14 one-year calendars, one for each common year (year that does not have a February 29) that starts on each day of the week, and one for each leap year that starts on each day of the week.

Common year starting on Sun - Mon - Tue - Wed - Thu - Fri - Sat
Leap year starting on   Sun - Mon - Tue - Wed - Thu - Fri - Sat This is the calendar for any common year starting on Sunday (dominical letter A). ... This is the calendar for a common year starting on Monday (dominical letter G), e. ... This is the calendar for a common year starting on Tuesday (dominical letter F), e. ... This is the calendar for a common year starting on Wednesday (dominical letter E), e. ... This is the calendar for any common year starting on Thursday (dominical letter D). ... This is the calendar for any common year starting on Friday (dominical letter C). ... This is the calendar for any common year starting on Saturday (dominical letter B) e. ... Here is a calendar for any leap year starting on Sunday (dominical letter AG). ... This is a calendar for a leap year starting on Monday (dominical letter GF). ... This is the calendar for a leap year starting on Tuesday (dominical letter FE) January February March Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 5 1 2 1 6 7 8 9... This is a calendar for any leap year starting on Wednesday (dominical letter ED) e. ... This is a calendar for any leap year starting on Thursday (dominical letter DC), e. ... This is the calendar for any leap year starting on a Friday (dominical letter CB). ... Here is the calendar for any leap year starting on Saturday (dominical letter BA), e. ...

Also certain calendar reforms may be considered to be perpetual calendars, such as the World calendar and International Fixed Calendar. Various reforms to the Gregorian calendar have been proposed. ... The World calendar often called the Worldsday Calendar is a proposed calendar as follows: There is no change in which years are leap years. ... This article needs to be wikified. ...