Method computeMonth

src/main/java/com/nlf/calendar/Lunar.java:304–344

计算干支纪月

()

   * 计算干支纪月
   */
  private void computeMonth() {
    Solar start = null;
    Solar end;
    String ymd = solar.toYmd();
    String time = solar.toYmdHms();
    int size = JIE_QI_IN_USE.length;

    //序号：大雪以前-3，大雪到小寒之间-2，小寒到立春之间-1，立春之后0
    int index = -3;
    for (int i = 0; i < size; i += 2) {
      end = jieQi.get(JIE_QI_IN_USE[i]);
      String symd = null == start ? ymd : start.toYmd();
      if (ymd.compareTo(symd) >= 0 && ymd.compareTo(end.toYmd()) < 0) {
        break;
      }
      start = end;
      index++;
    }

    //干偏移值（以立春当天起算）
    int offset = (((yearGanIndexByLiChun + (index < 0 ? 1 : 0)) % 5 + 1) * 2) % 10;
    monthGanIndex = ((index < 0 ? index + 10 : index) + offset) % 10;
    monthZhiIndex = ((index < 0 ? index + 12 : index) + LunarUtil.BASE_MONTH_ZHI_INDEX) % 12;

    start = null;
    index = -3;
    for (int i = 0; i < size; i += 2) {
      end = jieQi.get(JIE_QI_IN_USE[i]);
      String stime = null == start ? time : start.toYmdHms();
      if (time.compareTo(stime) >= 0 && time.compareTo(end.toYmdHms()) < 0) {
        break;
      }
      start = end;
      index++;
    }

    //干偏移值（以立春交接时刻起算）
    offset = (((yearGanIndexExact + (index < 0 ? 1 : 0)) % 5 + 1) * 2) % 10;
    monthGanIndexExact = ((index < 0 ? index + 10 : index) + offset) % 10;
    monthZhiIndexExact = ((index < 0 ? index + 12 : index) + LunarUtil.BASE_MONTH_ZHI_INDEX) % 12;
  }

  /**
   * 计算干支纪日