code: private Variants parseWeekdays(JsonObject calendar, String group) {
      JsonObject node = resolve(calendar, "days", group);
      return new Variants(
          weekdayMap(resolve(node, "abbreviated")),
          weekdayMap(resolve(node, "narrow")),
          weekdayMap(resolve(node, "short")),
          weekdayMap(resolve(node, "wide")));
    }
docs: Parse week day names of varying widths (W, Wed., Wednesday)