$re = '/(?<date>[^ ]+$)/m';
$str = '||pool-2-thread-1|| INFO com.tmobile.sfdc.reports.batch.listener.OrderJobListener - ORDER_JOB: ACTIVE at START_TIME: 2018-05-07T06:04:46.087Z';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php