- strtotime: documentation ( source)
<?php
// $arr = [0 => array('name' => 'coco', 'created_at' => array('sec' => 1444339210, 'usec' => 23000))];
//var_dump($arr);
// $filter = array_filter($arr, function($arr){
// return $arr['created_at']['sec'] > 1444339200 && $arr['created_at']['sec'] < 1444339220;
// });
// var_dump($filter);
$time = strtotime('01/07/2015' -1);
echo $time;