What is the maximum possible Mondays in one month?

5 mondays however this only applies on earth, depending on the planets orbit there could be more, for example: Saturn has an orbit of 10 759 earth days in a year, compared to earths 365 1/2 days per year. So taking into account there are 12 months in a "year" there are 896.58333333 days in a month. Therefore there can be over 128 "mondays in a month"