$re = '/(?:\s*(?<days>\d+)\s*days*)?(?:\s*(?<hours>\d+)\s*hours*)?(?:\s*(?<minutes>\d+)\s*minutes*)?/m';
$str = '1 day 15hours 08 minutes
1days 15 hour
15 hours 08minute
1 days 08 minutes
08minutes
15 hours
1 day';
preg_match_all($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