Two ways to change patterns in pathauto

First is to use hook_pathauto_pattern_alter and add some code to it like

function hook_pathauto_pattern_alter(&$pattern, array &$context) {
  // Switch out any [node:created:*] tokens with [node:updated:*] on update.
  if ($module == 'node' && ($context['op'] == 'update')) {
    $pattern = preg_replace('/\[node:created(\:[^]]*)?\]/', '[node:updated$1]', $pattern);
  }
}

where in context you will find all the date you need to match specific entity and language

Or you can use Variables and make a token out of it and it is i18n aware.
'localize' => TRUE,
'token' => TRUE,

/**
 * Implements hook_variable_info().
 */
function custom_variable_info($options) {

  $variables['support_pattern'] = array(
    'type' => 'text',
    'title' => t('Support Pathauto Variable', array(), $options),
    'description' => t('Variable for custom pathauto variable for taxonomy, "support" vocabulary', array(), $options),
    'required' => TRUE,
    'localize' => TRUE,
    'token' => TRUE, // We'll produce tokens automatically for this on
    );
  return $variables;
}