diff --git a/Doc/library/datetime.rst b/Doc/library/datetime.rst
--- a/Doc/library/datetime.rst
+++ b/Doc/library/datetime.rst
@@ -1597,6 +1597,13 @@
 or any other fixed-offset :class:`tzinfo` subclass (such as a class representing
 only EST (fixed offset -5 hours), or only EDT (fixed offset -4 hours)).
 
+.. seealso::
+
+   `pytz <http://pypi.python.org/pypi/pytz/>`_
+     While Python Standard Library has no :class:`zinfo` instances except UTC
+     there are `pytz` library which brings Olson timezone database to Python.
+
+     `pytz` is up-to-date info and recommended to use.
 
 .. _datetime-timezone: