<?php
function getDiff($date1,$date2){
    $date1 = date('y-m-d',strtotime($date1));
    $date2 = date('y-m-d',strtotime($date2));
    $now = new DateTime($date1);
    $ago = new DateTime($date2);
    $diff = $now->diff($ago);
//    print_r($diff);
    return $diff->days;
}
//echo date('Y-m-d',strtotime('01/08/2017'));
//echo getDiff('01/08/2017','08/07/2017');
echo getDiff('2017-08-05','2017-08-04');
//echo getDiff('2017/08/01','2017/07/08');

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