code: public static String isoDate(final Date val) {
      synchronized (isoDateFormat) {
        try {
          isoDateFormat.setTimeZone(Timezones.getDefaultTz());
        } catch (TimezonesException tze) {
          throw new RuntimeException(tze);
        }
        return isoDateFormat.format(val);
      }
    }
docs: Turn Date into "yyyyMMdd"
  
  @param val date
  @return String "yyyyMMdd"