SimplePie_Item::get_local_date

	 * languages other than the server's default, you need to change the locale
	 * with {@link http://php.net/setlocale setlocale()}. The available
	 * localizations depend on which ones are installed on your web server.
	 *
	 * @since 1.0
	 *
	 * @param string $date_format Supports any PHP date format from {@see http://php.net/strftime} (empty for the raw data)
	 * @return int|string|null
	 */
	public function get_local_date($date_format = '%c')
	{
		if (!$date_format)
		{
			return $this->sanitize($this->get_date(''), SIMPLEPIE_CONSTRUCT_TEXT);
		}