A calendar for Mars

In a generalized approach to calendar construction for Earth, two types of perpetual calendars (with dates fixed to the days of a week) were studied for Mars: with leap and skip days; and with leap and skip weeks. Calendars with skip days or weeks (omitted days or weeks) are preferable, because the frequency of skip years is appreciably lower than that of leap years. Unlike our terrestrial (Gregorian) calendar with a 2-parametric leap rule (periods of 4 and 400 years), a Mars calendar of comparable accuracy requires a 3-parametric rule with three periods. The rules derived possess this accuracy and represent an optimum solution. With the skip week calendar, which appears to be the best compromise for a calendar for Mars, an error of 1 day would occur (theoretically) in an interval >100,000 Martian years. (However, unknown secular changes in the length of the Martian year, an inaccuracy in the adopted value of its length, and possible non-uniform rotation of Mars, may affect the calendar accuracy over such long intervals of time.) A common year would have 672 Martian days distributed into 24 months of 28 days (of 4 weeks of 7 days each). In skip years a week at the end of the twelfth month would be omitted. The above most regular arrangement of months (corresponding to 12 bi-months) and a 7 day Martian week, also offer the possibility of conveniently adapting terrestrial month and day names to the calendar of Mars. The month names could be, e.g. Januarione, Januaryide; Februarione, Februaryide, etc., and those for days, e.g. Mondim, Tuesdim, etc.