$data2 = date('Y-m-d');
$data1 = $model->data_do;
 
$d1 = explode('-', $data1);
$y1 = $d1[0];
$m1 = $d1[1];
$dn1 = $d1[2];
 
$d2 = explode('-', $data2);
$y2 = $d2[0];
$m2 = $d2[1];
$dn2 = $d2[2];
 
$date1_set = mktime(0, 0, 0, $m1, $dn1, $y1);
$date2_set = mktime(0, 0, 0, $m2, $dn2, $y2);
 
$dni_do = ($date1_set - $date2_set) / (60 * 60 * 24);