function dty($sdate, $ldate) {
	$arr = array();
	$start    = (new DateTime($sdate))->modify('first day of this month');
	$end      = (new DateTime($ldate))->modify('first day of next month');
	$interval = DateInterval::createFromDateString('1 month');
	$period   = new DatePeriod($start, $interval, $end);


	foreach ($period as $dt) {
		$arr[] = $dt->format("Y-M");
	   // echo $dt->format("Y-M") . "<br>\n";
	}
	return $arr;
}
$tt = dty('2013-11', '2015-03');
print_r($tt);