filter by node_counter.timestamp

filter handler is missing for node_counter.timestamp field in statistics.views.inc

  // timestamp
  $data['node_counter']['timestamp'] = array(
    'title' => t('Most recent view'),
    'help' => t('The most recent time the node has been viewed.'),

    'field' => array(
      'handler' => 'views_handler_field_date',
      'click sortable' => TRUE,
    ),
+    'filter' => array(
+      'handler' => 'views_handler_filter_date',
+    ),
    'sort' => array(
      'handler' => 'views_handler_sort',
    ),
  );