</function>

  <function>
    <description>
      Returns formatted duration from a given value.
    </description>
    <name>formatDuration</name>
    <function-class>org.codelibs.fess.taglib.FessFunctions</function-class>
    <function-signature>java.lang.String formatDuration(long)</function-signature>
    <example>
      ${fe:formatDuration(1234)}
    </example>
  </function>

  <function>
    <description>

     * @param durationMillis the duration in milliseconds
     * @return formatted duration string (e.g., "2 days 14:30:25.123" or "14:30:25.123")
     */
    public static String formatDuration(final long durationMillis) {
        return DurationFormatUtils.formatDuration(durationMillis, "d 'days' HH:mm:ss.SSS").replace("0 days", StringUtil.EMPTY).trim();

    }

    /**
     * Formats a number using the specified pattern and user's locale.