program FridayThe13ths;
uses
SysUtils, DateUtils;
procedure FindFridayThe13ths(startYear, endYear: Integer);
var
year, month: Integer;
dt: TDateTime;
begin
for year := startYear to endYear do
begin
for month := 1 to 12 do
begin
dt := EncodeDate(year, month, 13);
if DayOfWeek(dt) = 6 then // 6 corresponds to Friday in Pascal's DayOfWeek function
Writeln('Friday the 13th: ', year, '-', Format('%.2d', [month]), '-13');
end;
end;
end;
begin
FindFridayThe13ths(2025, 2031);
end.
(*
run:
Friday the 13th: 2025-06-13
Friday the 13th: 2026-02-13
Friday the 13th: 2026-03-13
Friday the 13th: 2026-11-13
Friday the 13th: 2027-08-13
Friday the 13th: 2028-10-13
Friday the 13th: 2029-04-13
Friday the 13th: 2029-07-13
Friday the 13th: 2030-09-13
Friday the 13th: 2030-12-13
Friday the 13th: 2031-06-13
*)
