diff --git a/Doc/library/difflib.rst b/Doc/library/difflib.rst
index d749e14..8556e1d 100644
--- a/Doc/library/difflib.rst
+++ b/Doc/library/difflib.rst
@@ -146,8 +146,8 @@
 
    The context diff format normally has a header for filenames and modification
    times.  Any or all of these may be specified using strings for *fromfile*,
-   *tofile*, *fromfiledate*, and *tofiledate*. The modification times are normally
-   expressed in the format returned by :func:`time.ctime`.  If not specified, the
+   *tofile*, *fromfiledate*, and *tofiledate*.  The modification times are normally
+   expressed in the ISO 8601 format. If not specified, the
    strings default to blanks.
 
       >>> s1 = ['bacon\n', 'eggs\n', 'ham\n', 'guido\n']
@@ -281,8 +281,8 @@
 
    The context diff format normally has a header for filenames and modification
    times.  Any or all of these may be specified using strings for *fromfile*,
-   *tofile*, *fromfiledate*, and *tofiledate*. The modification times are normally
-   expressed in the format returned by :func:`time.ctime`.  If not specified, the
+   *tofile*, *fromfiledate*, and *tofiledate*.  The modification times are normally
+   expressed in the ISO 8601 format. If not specified, the
    strings default to blanks.
 
       >>> s1 = ['bacon\n', 'eggs\n', 'ham\n', 'guido\n']