public static TimeZone parseTimeZoneString(String timeZoneString) {
      TimeZone timeZone = TimeZone.getTimeZone(timeZoneString);
      if ("GMT".equals(timeZone.getID()) && !timeZoneString.startsWith("GMT")) {
         // We don't want that GMT fallback...
         throw new IllegalArgumentException("Invalid time zone specification '" + timeZoneString + "'");
      }
      return timeZone;
   }