code: private function format_e(&$str) {
      if (strstr($str, '%e') || strstr($str, '%T')) {
        $t   = $this->timescale == TimeScale::UTC() ? $this->timezone : $this->timescale;
        $str = str_replace('%e', $t, $str);
        $str = str_replace('%T', $t, $str);
      }
    }
docs: Timezone/Timescale identifier
  @param type $str