function daterange ($begin,$end,$interval='m'){
$begin = new datetime($begin);
$end = new datetime($end);
$end = $end->modify('+1 day');
$t ='p1'.$interval;
$interval = new dateinterval($t);
$daterange = new dateperiod($begin, $interval ,$end);
foreach($daterange as $date){
$range[]= $date->format(ymd);
}
return $range;
}