years = {1900, 2100}; months = {1 ,3 ,5 ,7 ,8 ,10 ,12}; result = Select[Tuples[{Range@@years, months}], (DateString[# ~ Join ~ 1, "DayNameShort"] == "Fri")&]; Print[result // Length," months with 5 weekends" ]; Print["First months: ", DateString[#,{"MonthName"," ","Year"}]& /@ result[[1 ;; 5]]]; Print["Last months: " , DateString[#,{"MonthName"," ","Year"}]& /@ result[[-5 ;; All]]]; Print[# // Length, " years without 5 weekend months:\n", #] &@ Complement[Range @@ years, Part[Transpose@result, 1]];