diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index cf3de80394..fc8017f2f3 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -10040,13 +10040,19 @@ EXTRACT(<replaceable>field</replaceable> FROM <replaceable>source</replaceable>)
     The <function>extract</function> function retrieves subfields
     such as year or hour from date/time values.
     <replaceable>source</replaceable> must be a value expression of
-    type <type>timestamp</type>, <type>time</type>, or <type>interval</type>.
-    (Expressions of type <type>date</type> are
-    cast to <type>timestamp</type> and can therefore be used as
-    well.)  <replaceable>field</replaceable> is an identifier or
+    type <type>timestamp</type>, <type>date</type>, <type>time</type>,
+    or <type>interval</type>.  (Timestamps and times can be with or
+    without time zone.)
+    <replaceable>field</replaceable> is an identifier or
     string that selects what field to extract from the source value.
+    Not all fields are valid for every input data type; for example, fields
+    smaller than a day cannot be extracted from a <type>date</type>, while
+    fields of a day or more cannot be extracted from a <type>time</type>.
     The <function>extract</function> function returns values of type
     <type>numeric</type>.
+   </para>
+
+   <para>
     The following are valid field names:
 
     <!-- alphabetical -->
@@ -10228,7 +10228,7 @@ SELECT EXTRACT(ISODOW FROM TIMESTAMP '2001-02-18 20:38:40');
       <listitem>
        <para>
         The <acronym>ISO</acronym> 8601 week-numbering year that the date
-        falls in (not applicable to intervals)
+        falls in
        </para>
 
 <screen>
@@ -10256,7 +10256,7 @@ SELECT EXTRACT(ISOYEAR FROM DATE '2006-01-02');
       <listitem>
        <para>
         The <firstterm>Julian Date</firstterm> corresponding to the
-        date or timestamp (not applicable to intervals).  Timestamps
+        date or timestamp.  Timestamps
         that are not local midnight result in a fractional value.  See
         <xref linkend="datetime-julian-dates"/> for more information.
        </para>