$re = '/(?<Details>.+?)\s-\s\d{4}Z/m';
$str = 'P3820 Houston to A345 Atlanta Line Down - 1339Z 19 May - On-going - TKT39390423
P3820 Houston to A345 Atlanta Line Down - 1339Z 19 May - 0834Z 20 May - TKT39390423
P3820 Houston to A345 Atlanta Line Down - 1339Z 19 MAY - Ongoing - TKT39390423 - 1339Z 19 May - On-going - TKT39390423
P3820 Houston - A345 Atlanta Line Down - 1339Z 19 MAY - Ongoing - INC39390423, DIRJ LLO MM#:394039 - 1339Z 19 May - On-going - TKT39390423
P3820 Houston - A345 Atlanta Line Down - 1339Z 19 MAY - 1834Z MAY - INC39390423, DIRJ LLO MM#:394039 - 1339Z 19 May - 0834Z 20 May - TKT39390423';
preg_match_all($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