Código PHP:
printf("<tr><td width='75'> %s</td><td width='75'> %s</td><td width='75'> %s</td><td width='175' align='right'> %s </td></tr>", $data->num_factura, date("d-m-Y",strtotime($data->fec_factura)), number_format($data->val_factura,0,",","."), date("d-m-Y",strtotime($data->fec_vencimi)));