PHP - Read xml and return a php array. Deal with date formating.

gistfile1.txt

/*
This function goes to the directory $pathDir, pass trough each all files inside it,
seeks for any file that math to the $searchString and reads it.
Return the content of all matched xml files within a php Array.
Ex: 
We have inside the FTP the follow files genereted by a CronJob: 
fileCarAudiRent2015.xml, fileCarAudiRent2016.xml, fileCarAudiSell2015.xm,
fileCarBMWRent2015.xml, fileCarBMWSell2016.xml, fileBoatWMBRent2015.xml, fileBoatWMBSell2015.xml,
fileBoatAudiRent2015.xml, fileBoatAudiSell2016.xml, ... .

We want to grab the content of all files that matches "Boat" string.
So, we need to do like this:
$arrInfo = read_XML_from_Folder_return_arrayAll("c:/Path_to_the_Folder","Boat");

We want to grab the content of all files that matches "Sell2015" string.
So, we need to do like this:
$arrInfo = read_XML_from_Folder_return_arrayAll("c:/Path_to_the_Folder","Sell2015");

We should inprove this function to match criteria like:
Give me all that has Sell AND 2015
Give me all that has Sell OR 2015
Give me all that has BMW AND 2015
...
*/


public function read_XML_from_Folder_return_arrayAll($pathDir,$searchString) {
              
	$xml_array="";
	$dir = new DirectoryIterator($pathDir); //http://php.net/manual/en/class.directoryiterator.php
	foreach ($dir as $fileinfo) {
	  if ($fileinfo->isFile()) {
			  $fileName = $fileinfo->getFilename();
			  //Macth rule
		  $pos = strpos($fileName, $searchString);
		  if ( $pos!== false) {//If match the sought string
	   		$filePath = $pathDir.$fileName;
			$xml = simplexml_load_file($filePath);
          		$xml_array [] = unserialize(serialize(json_decode(json_encode((array) $xml), 1)));  
					
			   /* If needed	
			   $invoice_date = $xml_array["Documents"]["InvoiceDate"];
			   $date = DateTime::createFromFormat('dmY', $invoice_date);//Formated date inside xml
			   $year = $date->format('Y');//Desired output year
			   $month = $date->format('M');//Desired output month 
			   */
					
		  }//End of if ( $pos!== false)                        
	  } 
	}
	//Testing
	echo "<pre>";
	  print_r($xml_array);
	echo "</pre>";
  

	return $xml_array;
 
 }