code: private boolean isDateSkeleton(String skeleton) {
      List<String> parts = Splitter.on('-').splitToList(skeleton);
      if (parts.size() > 1) {
        skeleton = parts.get(0);
      }
      for (Node node : DATETIME_PARSER.parse(skeleton)) {
        if (node instanceof Field) {
          Field field = (Field) node;
          switch (field.ch()) {
            case 'H':
            case 'h':
            case 'm':
            case 's':
              return false;
          }
        }
      }
      return true;
    }
docs: Indicates a skeleton represents a date based on the fields it contains.
  Any time-related field will cause this to return false.