i want code Expire soft on Year,Month,Day

procedure Form1_OnShow (Sender: string; Action: string);
var
   reg: TRegistry;
   iDays: integer;
begin
     reg := TRegistry.Create;
     reg.Access := KEY_ALL_ACCESS;
     reg.RootKey := HKEY_CURRENT_USER;
     reg.OpenKey('software\MyVisualDatabaseTrial',true);
     if not reg.ValueExists('StartDate') then reg.WriteDate('StartDate', Now+10); // trial period is 10 days

     iDays := Trunc(reg.ReadDate('StartDate')) - Trunc(Now); // time left days

     reg.CloseKey;
     reg.Free;

     if iDays < 1 then
     begin
          ShowMessage('Trial period is over.');
          Form1.Close;
     end;

     ShowMessage('Demo version. Time left: ' + IntToStr(iDays));
end;