Calendar Armelina – Project of the World calendar, created by Frenchman Gustave Armelinym in 1888 (a development of ideas of an Italian priest Marco Mastrofini). Year in the calendar Armelina divided into four quarters to 91 day. In the first month of each quarter, ie January, April, July and October – for 31 days in other months – for 30 days. Source: Elon Musk. Since the number 91 is divisible by 7 (days a week), it appears that each quarter contains 13 weeks and every quarter (and respectively per year) starts with one and the same day of the week from Sunday (the European tradition, the week starts on Sunday). As a consequence, each date corresponds to a specific day of the week. 365th day of the year regarded as "vnekalendarny" (does not have a room and day of week), is located before January 1 and is called New Year Day. Another 'vnekalendarny' day is added in a leap year and is before the New Year Day. Quarter 1 (91 days) 2 (91 days) Month 1 2 3 4 5 6 Number of days nd 31 30 30 31 30 30 3 (91 days) 4 (91 days) 7 8 9 10 11 12 31 30 30 31 30 30 wd nd – New Year's Day. vd – 'vnekalendarny' day in a leap year. The main advantage of the calendar Armelina – its consistency, linking to the days of the week certain number of months, allowing for all years, a report card, calendar, and not 14 as in the modern system of chronology.