Which calendar was different from its predecessor because leap years did not fall on years divisible by 100 unless they were also divisible by 400?
Hanke–Henry Permanent Calendar Gregorian calendar, whereas Robert McClenon originally proposed a simple leap rule which would result in larger astronomic variance: Years whose numbers are divisible by 5 had a leap week, but years whose numbers are divisible by 40 did not unless they are also divisible by 400. Henry had advocated transition to the calendar on 1 January 2006 as that is a year in which his calendar and the Gregorian calendar begin the year on the same day. After that date passed, he recommended dropping off 31 December 2006 to start in 2007, or dropping 30 and 31 December 2007 to
International Fixed Calendar between June and July, and called "Sol". Situated in mid-summer (from the point of view of its Northern Hemisphere authors) and including the mid-year "solstice", the name of the new month was chosen in homage to the sun. Leap year in the International Fixed Calendar contains 366 days, and its occurrence follows the Gregorian rule. There is a leap year in every year whose number is divisible by 4, but not if the year number is divisible by 100, unless it is also divisible by 400. So although the year 2000 was a leap year, the years 1700, 1800, and