$re = '/(?:0?\d|1[0-2]|jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)[ \/-](?:0?\d|1\d|2\d|3[0-1])[ \/-]\d{4}/m';
$str = '1/1/1987 09-21-2018 mar 8 1969 7 17 1975
';
preg_match_all($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