Why has a heptagon 7 sides and the month September is the 9 month?

Answer 1

Because the Romans, like many ancient cultures, considered the year to start at the beginning of Spring. That makes March the first month, and September the seventh month. And it continues on from there too: OCTober = 8 NOVember = 9 DECember = 10 If you have a Bible around the house, have a look at the descriptions of the Hebrew festivals in the Old Testament. Passover, which begins at the first Full Moon in Spring, is described as being celebrated in the "first month", whereas the festival of Sukkot ('Tabernacles') ... beginning at the first Full Moon in Autumn (the Harvest Moon) ... is described as a celebration in the "seventh month".