diff --git a/reference/datetime/datetime/createfromformat.xml b/reference/datetime/datetime/createfromformat.xml
index 68c5bf1b1b..31599105c6 100644
--- a/reference/datetime/datetime/createfromformat.xml
+++ b/reference/datetime/datetime/createfromformat.xml
@@ -50,6 +50,15 @@
     </varlistentry>
    </variablelist>
   </para>
+  <para>
+   If the first character of <parameter>format</parameter>
+   is <literal>!</literal>, then portions of the date/time value
+   generated which are not specified in
+   <parameter>time</parameter> will be initialized to zero. If the
+   first character of <parameter>format</parameter> is
+   not <literal>!</literal> then portions of the date/time value
+   generated will be initialized to the current system time.
+  </para>
  </refsect1>
 
  <refsect1 role="returnvalues">