时间的运算

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;