src/Marando/AstroDate/Traits/FormatTrait.php
private function format_n(&$str) {
    if (strstr($str, '%n'))
      $str = str_replace('%n', sprintf('%01d', $this->month), $str);
  }
private function format_n(&$str) {
    if (strstr($str, '%n'))
      $str = str_replace('%n', sprintf('%01d', $this->month), $str);
  }
Numeric representation of a month, without leading zeros
@param type $str