procedure TForm1.Button1Click(Sender: TObject);var  i: Real;begin  i := StrToDate('2008-1-1') - StrToDate('2007-1-1');  ShowMessage(FloatToStr(i));  //返回的结果是365天  i := StrToDate('2009-1-1') - StrToDate('2008-1-1');  ShowMessage(FloatToStr(i));  //返回的结果是366天end;