code: public static String convertInstantToZulu( final Instant instant )
      {
          if ( instant == null )
          {
              throw new NullPointerException();
          }
  
          try
          {
              return EDIR_TIMESTAMP_FORMATTER.format( instant.atZone( ZoneOffset.UTC ) );
          }
          catch ( DateTimeParseException e )
          {
              throw new IllegalArgumentException( "unable to format zulu time-string: " + e.getMessage() );
          }
      }
docs: Convert a Instant to the Zulu String format.
  See the <a href="http://developer.novell.com/documentation/ndslib/schm_enu/data/sdk5701.html">eDirectory Time attribute syntax definition</a> for more details.
  
  @param instant The Date to be converted
  @return A string formatted such as "199412161032Z".