Date Exposed Filters - change dropdown labels

I've been at this all day and can't nail it.
I want to remove the hyphen from in -Year, -Month etc. and capitalize the words.
I created a custom module but can't identify the correct variables in the: $form[] = t('')
Anyone done this before successfully...?
Thanks for any help.

<?php
/**
 * Change default labels on Date dropdown menus, e.g. -Year, -Month, -Day, etc.
 */
function date_label_changer_form_alter(&$form, &$form_state, $form_id) {
  if ($form_id == 'views_exposed_form' && $form['#id'] == 'views-exposed-form-worldmap-page-1') {
      $form['date_filter']['min']['year']['#label'] = t('YEAR'); 
  }
}