*/
PHP_FUNCTION(timezone_identifiers_list)
{
	const timelib_tzdb             *tzdb;
	const timelib_tzdb_index_entry *table;
	int                             i, item_count;
	long                            what = PHP_DATE_TIMEZONE_GROUP_ALL;
	char                           *option = NULL;
	int                             option_len = 0;

	if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "|ls", &what, &option, &option_len) == FAILURE) {
		RETURN_FALSE;
	}

	/* Extra validation */
	if (what == PHP_DATE_TIMEZONE_PER_COUNTRY && option_len != 2) {
		php_error_docref(NULL TSRMLS_CC, E_NOTICE, "A two-letter ISO 3166-1 compatible country code is expected");
		RETURN_FALSE;
	}

	tzdb = DATE_TIMEZONEDB;
	item_count = tzdb->index_size;
	table = tzdb->index;
	
	array_init(return_value);

	for (i = 0; i < item_count; ++i) {
		if (what == PHP_DATE_TIMEZONE_PER_COUNTRY) {
			if (tzdb->data[table[i].pos + 5] == option[0] && tzdb->data[table[i].pos + 6] == option[1]) {
				add_next_index_string(return_value, table[i].id, 1);
			}
		} else if (what == PHP_DATE_TIMEZONE_GROUP_ALL_W_BC || (check_id_allowed(table[i].id, what) && (tzdb->data[table[i].pos + 4] == '\1'))) {
			add_next_index_string(return_value, table[i].id, 1);
		}
	};
Unknown