Source code in the pascal programming language

program long_year(input);
  var
    y: integer;

  function rd_dec31(year: integer): integer;
  begin
    { Rata Die of Dec 31, year }
    rd_dec31 := year * 365 + year div 4 - year div 100 + year div 400
  end;

  function rd_jan1(year: integer): integer;
  begin
    rd_jan1 := rd_dec31(year - 1) + 1
  end;

  function weekday(rd: integer): integer;
  begin
    weekday := rd mod 7;
  end;

  function long_year(year: integer): boolean;
  var
    jan1: integer;
    dec31: integer;
  begin
    jan1 := rd_jan1(year);
    dec31 := rd_dec31(year);
    long_year := (weekday(jan1) = 4) or (weekday(dec31) = 4)
  end;

  begin
    for y := 1990 to 2050 do
      if long_year(y) then
        writeln(y)
  end.


program Long_year;

uses
  SysUtils,
  DateUtils;

  procedure PrintLongYears(StartYear, EndYear: Uint32);
  var
    Year, Count: Uint32;
    DateSep: char;
  begin
    DateSep := FormatSettings.DateSeparator;
    Writeln('Long years between ', StartYear, ' and ', EndYear);
    Count := 0;
    for Year := StartYear to EndYear do
      if WeeksInYear(StrToDate('01' + DateSep + '01' + DateSep + IntToStr(Year))) = 53 then
      begin
        if Count mod 10 = 0 then
          Writeln;
        Write(Year, ' ');
        Inc(Count);
      end;
    if Count mod 10 <> 0 then
      Writeln;
    writeln('Found ', Count, ' long years between ', StartYear, ' and ', EndYear);
  end;

begin
  PrintLongYears(1800, 2100);
  {$IFDEF WINDOWS}
  Readln;
  {$ENDIF}
end.