In a calendar year, how many months, maximum, can start on a Sunday? What will be the next (very unlucky?) year when this maximum occurs?

Must every calendar year have at least one month that starts on a Sunday?

The Eastman Kodak Company adopted and used the International Fixed Calendar from 1928 to 1989. This calendar had thirteen months of 28 days each. Each month began on a Sunday, thus the maximum number of months in a year using this calendar that 'start on a Sunday' is thirteen.
It is unknown when there will be an official calendar reform that may increase the number of months. 
Of the current adopted Gregorian calendar, the most number of months that begin on the same day is three (for non-leap years: January-April-July, or for leap years: February-March-November).
The next year, as of this year 2013, that will have three Sunday-starting months will be 2017.
Every calendar year using the currently adopted Gregorian calendar will have at least one month that will start on a Sunday.

Posted by Dej Mar on 2013-06-13 05:08:14