时间戳问题PHP

Question

i have this code and i have problem in Datetime() if i get timestamp in my database he working fine but after go to another page and come back to this page code every time the counter come back to 1 seconde and starts counting again

but when use the timestamp directly like this counter work fine

$then = new DateTime('2016-03-18 23:47:41' , new DateTimeZone('Europe/London'));

this code when get timestamp in database e_time column give him timestamp type

 <?php
    $stmt = $DB_con->prepare("SELECT * FROM `post` WHERE `e_stauts`=1 AND `lockin`=1 ORDER BY `id` DESC");
    $stmt->execute();   
  }
    foreach ($stmt->fetchAll() as $row) {
    echo"".$row['e_title']." </br>";

    $then = new DateTime(''.$row['e_time'].'' , new DateTimeZone('Europe/London'));
    $now = new DateTime();
    $delta = $now->diff($then);

    $quantities = array(
        'year' => $delta->y,
        'month' => $delta->m,
        'day' => $delta->d,
        'hour' => $delta->h,
        'minute' => $delta->i,
        'second' => $delta->s); 

    if($quantities['day'] != 0){
    echo "".$quantities['day']." Day   ".'</br>';   
    }elseif($quantities['day'] == 0 & $quantities['hour'] > 0){
    echo "".$quantities['hour']." Hour  ".'</br>';    
    }elseif($quantities['hour'] == 0 & $quantities['minute'] > 0){
    echo "".$quantities['minute']." Minute   ".'</br>';    
    }elseif($quantities['minute'] == 0 & $quantities['second'] > 0){
    echo "".$quantities['second']." Seconde   ".'</br>';    
    }
     }