src/Marando/AstroDate/Traits/FormatTrait.php
private function formatS(&$str) {
    if (strstr($str, '%S'))
      $str = str_replace('%S', static::ordinal($this->day), $str);
  }
private function formatS(&$str) {
    if (strstr($str, '%S'))
      $str = str_replace('%S', static::ordinal($this->day), $str);
  }
English ordinal suffix for the day of the month, 2 characters
@param type $str