Method next

src/main/java/com/nlf/calendar/SolarSeason.java:130–133

季度推移 @param seasons 推移的季度数，负数为倒推 @return 推移后的季度

(int seasons)

   * @return 推移后的季度
   */
  public SolarSeason next(int seasons) {
    SolarMonth m = SolarMonth.fromYm(year, month).next(MONTH_COUNT * seasons);
    return new SolarSeason(m.getYear(), m.getMonth());
  }

  /**
   * 获取本季度的月份