How do you calculate months worked per year?

Totally there is 365 days per year. But Months have 30 and 31 days in them. so for example if 73 days worked then its is 31 plus 28 plus 14 days. we have to write 31 Jan. plus 28 Feb. plus 31 Mar plus etc. and see which span of addition your number comes. In example 73 equals 31 plus 28 plus 14 so it is 2 months and 14 days worked per year.