diff --git a/Doc/lib/libbasehttp.tex b/Doc/lib/libbasehttp.tex
index fe794f8..64c069f 100644
--- a/Doc/lib/libbasehttp.tex
+++ b/Doc/lib/libbasehttp.tex
@@ -217,11 +217,16 @@
 of the \member{server_version} and \member{sys_version} class variables.
 \end{methoddesc}
 
-\begin{methoddesc}{date_time_string}{}
-Returns the current date and time, formatted for a message header.
+\begin{methoddesc}{date_time_string}{\optional{timestamp}}
+Returns the date and time given by \var{timestamp} (which must be in the
+format returned by \function{time.time()}), formatted for a message header.
+If \var{timestamp} is omitted, it uses the current date and time.
+
+The result looks like \code{'Sun, 06 Nov 1994 08:49:37 GMT'}.
+\versionadded[The \var{timestamp} parameter]{2.5}
 \end{methoddesc}
 
-\begin{methoddesc}{log_data_time_string}{}
+\begin{methoddesc}{log_date_time_string}{}
 Returns the current date and time, formatted for logging.
 \end{methoddesc}
 
diff --git a/Doc/lib/libsimplehttp.tex b/Doc/lib/libsimplehttp.tex
index c30eaa8..efb40ec 100644
--- a/Doc/lib/libsimplehttp.tex
+++ b/Doc/lib/libsimplehttp.tex
@@ -65,13 +65,18 @@
 \var{extensions_map} variable.
 
 A \code{'Content-type:'} header with the guessed content type is
-output, followed by a blank line signifying the end of the headers,
+output, followed by a \code{'Content-Length:'} header with the file's
+size and a \code{'Last-Modified:'} header with the file's modification
+time.
+
+Then follows a blank line signifying the end of the headers,
 and then the contents of the file are output. If the file's MIME type
 starts with \code{text/} the file is opened in text mode; otherwise
 binary mode is used.
 
 For example usage, see the implementation of the \function{test()}
 function.
+\versionadded[The \code{'Last-Modified'} header]{2.5}
 \end{methoddesc}