Create a Custom, Sortable Column for a Taxonomy. See http://cfxdesign.com/create-a-custom-sortable-column-for-a-taxonomy

create_date_column_for_issues.php

<?php

function create_date_column_for_issues($issue_columns) {
  $issue_columns['date'] = 'Date';
  return $issue_columns;
}
add_filter('manage_edit-issue_columns', 'create_date_column_for_issues');

populate_date_column_for_issues.php

<?php

function populate_date_column_for_issues($value, $column_name, $term_id) {
  $issue = get_term($term_id, 'issue');
  $date = DateTime::createFromFormat('Ymd', get_field('issue-date', $issue));
  switch($column_name) {
    case 'date': 
      $value = $date->format('Y/m/d');
    break;

    default:
    break;
  }
  return $value;    
}
add_filter('manage_issue_custom_column', 'populate_date_column_for_issues', 10, 3);

register_date_column_for_issues_sortable.php

<?php

function register_date_column_for_issues_sortable($columns) {
  $columns['date'] = 'issue_date';
  return $columns;
}
add_filter('manage_edit-issue_sortable_columns', 'register_date_column_for_issues_sortable');

sort_issues_by_date.php

<?php

function sort_issues_by_date($pieces, $taxonomies, $args) {
  global $pagenow;
  if(!is_admin()) {
    return $pieces;
  }

  if(is_admin() && $pagenow == 'edit-tags.php' && $taxonomies[0] == 'issue') {
    $orderby = isset($_REQUEST['orderby']) ? trim(wp_unslash($_REQUEST['orderby'])) : 'issue-date';
    $order   = isset($_REQUEST['order'])   ? trim(wp_unslash($_REQUEST['order']))   : 'DESC';

    if($orderby == 'issue-date') {
      $pieces['join']   .= " INNER JOIN wp_options AS opt ON opt.option_name = concat('issue_',t.term_id,'_".$orderby."')";
      $pieces['orderby'] = "ORDER BY opt.option_value";
      $pieces['order']   = $order;
    }
  }

  return $pieces;
}
add_filter('terms_clauses', 'sort_issues_by_date', 10, 3);