- preg_match_all: documentation ( source)
<?php
$string = "Patient will come in earlier\n\nPacket emailed 2012-06-14 11:30:06\n\nPacket emailed 2012-06-12 12:32:04";
$pattern = "/packet (e{0,1}mailed) \d{4}-(\d{2}-\d{2})/i";
preg_match_all($pattern,$string,$matches,PREG_SET_ORDER);
//print_r($matches[count($matches)-1]);
echo $matches[count($matches)-1][1];
?>