Marco Mastrofini (1763–1845) was an Italian priest, philosopher and mathematician. History of work In 1834 Mastrofini offered to create for the world an "eternal" calendar, and demonstrated that its invariance can be achieved only by application of special intercalary days that would belong to any week or month. He offered to establish a calendar year of 364 days split into 52 seven-day weeks, and to place the 365th day of each year at the end of December, considering it special or out of week. He planned one more special day in a leap year, and to place it in the middle of a year, between the last day of June and the first day of July, or following the first special day. Influence on other calendars His work significantly influenced the Armelin's calendar and calendar reform proposal by Auguste Comte in 1849. References Marco Mastrofini Bio 1763 births 1845 deaths People from Monte Compatri 19th-century Italian Roman Catholic priests 18th-century Italian mathematicians 19th-century Italian mathematicians