$predate = date("D", mktime(0, 0, 0, $month, $day, $year));

echo $predate;

switch($predate) {
  case "Sun":
  $pre2 = 0;
  break;
  case "Mon":
  $pre2 = 1;
  break;
  case "Tue":
  $pre2 = 2;
  break;
  case = "Wed":
  $pre2 = 3;
  break;
  case = "Thu":
  $pre2 = 4;
  break;
  case = "Fri":
  $pre2 = 5;
  break;
 case = "Sat":
  $pre2 = 6;
  break;
}