* @param mixed Date format (string or int; see date formats in the Chamilo system: TIME_NO_SEC_FORMAT, DATE_FORMAT_SHORT, DATE_FORMAT_LONG, DATE_TIME_FORMAT_LONG, DATE_FORMAT_LONG_WITHOUT_DAY)
* @param mixed Date format (string or int; see date formats in the Chamilo system: TIME_NO_SEC_FORMAT, DATE_FORMAT_SHORT, DATE_FORMAT_LONG, DATE_TIME_FORMAT_LONG)
* @param string $language (optional) Language indentificator. If it is omited, the current interface language is assumed.