$re = '/201410[0-3][0-9]/';
$str = '20141001
20141002
20141003
20141004
20141005
20141006
20141007
20141008
20141009
20141010
20141011
20141012
20141013
20141014
20141015
20141016
20141017
20141018
20141019
20141020
20141021
20141022
20141023
20141024
20141025
20141026
20141027
20141028
20141029
20141030
';
preg_match_all($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