firstyear = 2000; lastyear = 2099; years = Range[firstyear, lastyear]; firstday = Table[DayName[{years[[n]], 01, 01}], {n, Length[years]}]; lastday = Table[DayName[{years[[n]], 12, 31}], {n, Length[years]}]; Table[If[years[[n]] >= 1582, If[firstday[[n]] == Thursday || lastday[[n]] == Thursday, Style[years[[n]] " long year \n", Bold, Red] , years[[n]] " short \n"], "error \n"], {n, Length[years]}]