Change Date format on Views BEF

There are several methodes.

Change date format Using custom module.

1. Create a module and use he hook hook_form_views_exposed_form_alter(&$form, &$form_state);

Example:

function mymodule_form_views_exposed_form_alter(&$form, &$form_state){

  $date_format = "d-m-Y";

  $date_fields = array(

    'node_changed',

    'field_myfield_eventdate',

  );

  foreach ($date_fields as $field) {

    if (!empty($form[$field])) {

      if (!empty($form[$field]['#date_format'])) {

        $form[$field]['#date_format'] = $date_format;

      }

      if (!empty($form[$field]['min']['#date_format'])) {

        $form[$field]['min']['#date_format'] = $date_format;

      }

      if (!empty($form[$field]['max']['#date_format'])) {

        $form[$field]['max']['#date_format'] = $date_format;

      }

      if (!empty($form[$field]['value']['#date_format'])) {

        $form[$field]['value']['#date_format'] = $date_format;

      }

    }

  }

}

2. Change date popup format by JS/jQuery or by hook_js_alter(&$js)

2.1 By hook_js_alter

function mymodule_js_alter(&$js) {

  $js['settings']['data'][] = array('better_exposed_filters'=> array('bef_dateformat'=>'dd-mm-yy'));

}

2.2 By JS/jQuers : Add following js (How to add a javascript)

$('.bef-datepicker').datepicker({ dateFormat: 'dd-mm-yy' });