-zend_class_entry *php_pqdt_class_entry;
-zval *php_pqdt_from_string(char *datetime_str, size_t datetime_len, char *fmt, zval *zv TSRMLS_DC);
-void php_pqdt_to_string(zval *zdt, const char *format, char **str_buf, size_t *str_len TSRMLS_DC);
+extern zend_class_entry *php_pqdt_class_entry;
+extern zval *php_pqdt_from_string(zval *zv, char *input_fmt, char *dt_str, size_t dt_len, char *output_fmt, zval *ztimezone TSRMLS_DC);
+extern void php_pqdt_to_string(zval *zdt, const char *format, char **str_buf, size_t *str_len TSRMLS_DC);