// 2018/2/13 00:26:00.000

function format_date($date, $format='Y-m-d H:i:s') {

    if(empty($date)) return $date;

    $arr = preg_split("/[\s\/:.-]+/", $date);

    $year = intval($arr[0]);

    $month = intval($arr[1]);

    $day = intval($arr[2]);

    $hour = intval($arr[3]);

    $minute = intval($arr[4]);

    $second = intval($arr[5]);

    $time = mktime($hour, $minute, $second, $month, $day, $year);

    return date($format, $time);

}

$date = format_date($date);

echo($date);

2018-02-13 00:26:00