code: public static String isoDateTime(final Date val, final TimeZone tz) {
      synchronized (isoDateTimeTZFormat) {
        isoDateTimeTZFormat.setTimeZone(tz);
        return isoDateTimeTZFormat.format(val);
      }
    }
docs: Turn Date into "yyyyMMddTHHmmss" for a given timezone
  
  @param val date
  @param tz TimeZone
  @return String "yyyyMMddTHHmmss"