Exposed date select list in descending order
You can do this via hook_form_alter().

function myModule_form_alter(&amp;$form, &amp;$form_state, $form_id) {
  if ($form_id == 'views_exposed_form' &amp;&amp; $form['#id'] == 'FORM-UNIQUE-ID') {
    $form['field_MY_FIELD_value']['value']['#process'][] = date_select_desc_element_process;
  }
}