function DaysOfMonth(mm, yy: Integer): Integer;
begin
if mm = 2 then
begin
Result := 28;
if IsLeapYear(yy) then Result := 29;
end
else
begin
if mm < 8 then
begin
if (mm mod 2) = 0 then
Result := 30
else
Result := 31;
end
else
begin
if (mm mod 2) = 0 then
Result := 31
else
Result := 30;
end;
end;
end;
procedure TForm1.Button1Click(Sender: TObject);
var
days: Integer;
begin
days := DaysOfMonth(7, 2001);
ShowMessage('July 2001 has ' + IntToStr(days) + ' days');
end;