<?php $re = '~(0[1-9]|1[0-2])/[0-9]{4}~'; $str = "03/201408/201511/201203/201408/201511/201203/201408/201511/2012";
Standard input is empty
Array
(
[0] => 03/2014
[1] => 08/2015
[2] => 11/2012
[3] => 03/2014
[4] => 08/2015
[5] => 11/2012
[6] => 03/2014
[7] => 08/2015
[8] => 11/2012
)