added strftime
diff --git a/Doc/lib/libtime.tex b/Doc/lib/libtime.tex
index 746e21e..56488d1 100644
--- a/Doc/lib/libtime.tex
+++ b/Doc/lib/libtime.tex
@@ -94,6 +94,13 @@
be a floating point number to indicate a more precise sleep time.
\end{funcdesc}
+\begin{funcdesc}{strftime}{format, tuple}
+Convert a tuple representing a time as returned by \code{gmtime()} or
+\code{localtime()} to a string as specified by the format argument.
+See the \code{strftime(3)} man page for details of the syntax of
+format strings.
+\end{funcdesc}
+
\begin{funcdesc}{time}{}
Return the time as a floating point number expressed in seconds since
the epoch, in UTC. Note that even though the time is always returned