Refer to strftime(3) manpage for platform specific format codes.
Suggested by Skip Montanaro on docs@.
diff --git a/Doc/library/time.rst b/Doc/library/time.rst
index 1e21fb6..cc8f716 100644
--- a/Doc/library/time.rst
+++ b/Doc/library/time.rst
@@ -471,8 +471,10 @@
>>> strftime("%a, %d %b %Y %H:%M:%S +0000", gmtime())
'Thu, 28 Jun 2001 14:17:15 +0000'
- Additional directives may be supported on certain platforms, but only the ones
- listed here have a meaning standardized by ANSI C.
+ Additional directives may be supported on certain platforms, but only the
+ ones listed here have a meaning standardized by ANSI C. To see the full set
+ of format codes supported on your platform, consult the :manpage:`strftime(3)`
+ documentation.
On some platforms, an optional field width and precision specification can
immediately follow the initial ``'%'`` of a directive in the following order;