Calendar, GREG OR I AN

The true length of the year is 365d. 5h. 48m. 47.8s.; the Julian year is therefore too long by 11m. 14s., or a little more than 3 days in 400 years. Accord ingly, in 1582, Pope Gregory XIII. introduced the following changes: the error of 10 days, which had accumulated since the Council of Nice, was corrected; and it was provided that for the future all centenary years not divisible by 400 should be common years of 365 days. (The year 1900 is divisible by 4, but not by 400. It will therefore be counted as a common year of 365 days.) The outstanding error will amount to one day only after the expiration of 3,323 years.