كيفية تغيير التاريخ والوقت بواسطة برنامج -delphi-

procedure TForm1.Button1Click(Sender: TObject);
var
  SystemTime: TSystemTime;
  dDate: TDate;
  mTime: TTime;
begin
// '16/07/2015'  or  '16-07-2015' and '10:15:00' for Windows XP 32bit
  dDate := StrToDate(Edit1.Text);
  mTime := StrToTime(Edit2.Text);
  DateTimeToSystemTime(dDate + mTime, SystemTime);
  SetLocalTime(SystemTime);
  PostMessage(HWND_BROADCAST, WM_TIMECHANGE, 0, 0);
end;

procedure TForm1.FormShow(Sender: TObject);
begin
 Label1.Caption := 'Entrez Date';
 Label1.Caption := 'Entrez Time';
 Edit1.Text :=DateToStr(Now);
 Edit2.Text :=TimeToStr(Now);
 Button1.Enabled := false;
end;

procedure TForm1.Edit1Change(Sender: TObject);
begin
 if(Edit1.Text <> '')or(Edit2.Text <> '')then
  Button1.Enabled := true else Button1.Enabled := false;
end;

procedure TForm1.Edit2Change(Sender: TObject);
begin
 Edit1Change(Sender);
end;