<entry><literal>allballs</literal></entry>
          <entry><type>time</type></entry>
          <entry>00:00:00.00 UTC</entry>
         </row>
        </tbody>
       </tgroup>
      </table>

     <para>
      The following <acronym>SQL</acronym>-compatible functions can also
      be used to obtain the current time value for the corresponding data
      type:
      <literal>CURRENT_DATE</literal>, <literal>CURRENT_TIME</literal>,
      <literal>CURRENT_TIMESTAMP</literal>, <literal>LOCALTIME</literal>,
      <literal>LOCALTIMESTAMP</literal>.  (See <xref
      linkend="functions-datetime-current"/>.)  Note that these are
      SQL functions and are <emphasis>not</emphasis> recognized in data input strings.
     </para>

     <caution>
      <para>
       While the input strings <literal>now</literal>,
       <literal>today</literal>, <literal>tomorrow</literal>,
       and <literal>yesterday</literal> are fine to use in interactive SQL
       commands, they can have surprising behavior when the command is
       saved to be executed later, for example in prepared statements,
       views, and function definitions.  The string can be converted to a
       specific time value that continues to be used long after it becomes
       stale.  Use one of the SQL functions instead in such contexts.
       For example, <literal>CURRENT_DATE + 1</literal> is safer than
       <literal>'tomorrow'::date</literal>.
      </para>
     </caution>

    </sect3>
   </sect2>

   <sect2 id="datatype-datetime-output">
    <title>Date/Time Output</title>

    <indexterm>
     <primary>date</primary>
     <secondary>output format</secondary>
     <seealso>formatting</seealso>
    </indexterm>

    <indexterm>
     <primary>time</primary>
     <secondary>output format</secondary>
     <seealso>formatting</seealso>
    </indexterm>

    <para>
     The output format of the date/time types can be set to one of the four
     styles ISO 8601,
     <acronym>SQL</acronym> (Ingres), traditional <productname>POSTGRES</productname>
     (Unix <application>date</application> format), or
     German.  The default
     is the <acronym>ISO</acronym> format.  (The
     <acronym>SQL</acronym> standard requires the use of the ISO 8601
     format.  The name of the <quote>SQL</quote> output format is a
     historical accident.)  <xref
     linkend="datatype-datetime-output-table"/> shows examples of each
     output style.  The output of the <type>date</type> and
     <type>time</type> types is generally only the date or time part
     in accordance with the given examples.  However, the
     <productname>POSTGRES</productname> style outputs date-only values in
     <acronym>ISO</acronym> format.
    </para>

     <table id="datatype-datetime-output-table">
      <title>Date/Time Output Styles</title>
      <tgroup cols="3">
       <colspec colname="col1" colwidth="1*"/>
       <colspec colname="col2" colwidth="1*"/>
       <colspec colname="col3" colwidth="2*"/>
       <thead>
        <row>
         <entry>Style Specification</entry>
         <entry>Description</entry>
         <entry>Example</entry>
        </row>
       </thead>
       <tbody>
        <row>
         <entry><literal>ISO</literal></entry>
         <entry>ISO 8601, SQL standard</entry>
         <entry><literal>1997-12-17 07:37:16-08</literal></entry>
        </row>
        <row>
         <entry><literal>SQL</literal></entry>
         <entry>traditional style</entry>
         <entry><literal>12/17/1997 07:37:16.00 PST</literal></entry>
        </row>
        <row>
         <entry><literal>Postgres</literal></entry>
         <entry>original style</entry>
         <entry><literal>Wed Dec 17 07:37:16 1997 PST</literal></entry>
        </row>
        <row>
         <entry><literal>German</literal></entry>
         <entry>regional style</entry>
         <entry><literal>17.12.1997 07:37:16.00 PST</literal></entry>
        </row>
       </tbody>
      </tgroup>
     </table>

    <note>
     <para>