Solar circle
The solar circle or solar cycle , not to be confused with the sunspot cycle , is a term from the Easter calculation . It is a cycle that has a period of 28 years in the Julian calendar . After this time, a new series of 28 assignments between calendar dates and weekdays begins . In the case of the Easter bill, the assignment to Sundays is of interest , since Easter must always be a Sunday. It is the first Sunday after the spring full moon , which is dated with the help of the lunar circle . In the computus , the medieval algorithm of this calculation, the numbers 1 to 28 were assigned to the 28 years of a series as solar circles SZ . Another coding of the years was done with the help of the Sunday letter .
The period of 28 years is the smallest common multiple of the 7 days of the week and the switching period of 4 years: in normal years, the days of the week are each 1; in leap years, each is 2 less. In the Gregorian calendar , 3 switching operations fail in 400 years. The solar circle has a period of 400 years in it. There is no increase because 400 Gregorian years contain an integer number of weeks.
See also
Individual proof
- ^ Heinz Zemanek : Calendar and Chronology, Oldenbourg, 1990, ISBN 3-486-20927-2 , p. 35