Add documentation example of using interval multiplication with 'days'.

Backpatch to 8.1.X.

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 1aaf6e1387372fcf3d315c341cc2d75d81d9925f..70d686c351dcbbdfddf440717badacd8a8b6776f 100644 (file)
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -5199,6 +5199,12 @@ SELECT SUBSTRING('XY1234Z', 'Y*?([0-9]{1,3})');
         <entry><literal>interval '00:15:00'</literal></entry>
        </row>
 
+       <row>
+        <entry> <literal>*</literal> </entry>
+        <entry><literal>21 * interval '1 day'</literal></entry>
+        <entry><literal>interval '21 days'</literal></entry>
+       </row>
+
        <row>
         <entry> <literal>*</literal> </entry>
         <entry><literal>double precision '3.5' * interval '1 hour'</literal></entry>