小程序获取农历，阳历转农历，计算属相

代码

在utils.js中新建js，命名为calendar.js，粘贴入以下代码：

/*
 * 阳历转农历：
 * getLunarDate: getLunarDate
 * 返回值格式：yyyy-MM-DD
 * 
 *
 * 获取农历信息：
 * getLunarDateString: getLunarDateString
 * 返回值格式：{day: "一",dz: "未",month: "腊",tg: "辛",year: "羊"} 
 *
*/
let lunar = {
  tg: '甲乙丙丁戊己庚辛壬癸',
  dz: '子丑寅卯辰巳午未申酉戌亥',
  number: '一二三四五六七八九十',
  year: '鼠牛虎兔龙蛇马羊猴鸡狗猪',
  month: '正二三四五六七八九十冬腊',
  monthadd: [0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334],
  calendar: [0xA4B, 0x5164B, 0x6A5, 0x6D4, 0x415B5, 0x2B6, 0x957, 0x2092F, 0x497, 0x60C96, 0xD4A, 0xEA5, 0x50DA9, 0x5AD, 0x2B6, 0x3126E, 0x92E, 0x7192D, 0xC95, 0xD4A, 0x61B4A, 0xB55, 0x56A, 0x4155B, 0x25D, 0x92D, 0x2192B, 0xA95, 0x71695, 0x6CA, 0xB55, 0x50AB5, 0x4DA, 0xA5B, 0x30A57, 0x52B, 0x8152A, 0xE95, 0x6AA, 0x615AA, 0xAB5, 0x4B6, 0x414AE, 0xA57, 0x526, 0x31D26, 0xD95, 0x70B55, 0x56A, 0x96D, 0x5095D, 0x4AD, 0xA4D, 0x41A4D, 0xD25, 0x81AA5, 0xB54, 0xB6A, 0x612DA, 0x95B, 0x49B, 0x41497, 0xA4B, 0xA164B, 0x6A5, 0x6D4, 0x615B4, 0xAB6, 0x957, 0x5092F, 0x497, 0x64B, 0x30D4A, 0xEA5, 0x80D65, 0x5AC, 0xAB6, 0x5126D, 0x92E, 0xC96, 0x41A95, 0xD4A, 0xDA5, 0x20B55, 0x56A, 0x7155B, 0x25D, 0x92D, 0x5192B, 0xA95, 0xB4A, 0x416AA, 0xAD5, 0x90AB5, 0x4BA, 0xA5B, 0x60A57, 0x52B, 0xA93, 0x40E95],
};
// 获取阴历日期
const getLunarDate = (date) => {
  let useDate = new Date();
  let year,
    month,
    day;
  if (!date) {
    date = new Date(), year = date.getFullYear(), month = date.getMonth(), day = date.getDate();
  } else {
    date = date.split('-'), year = parseInt(date[0]), month = date[1] - 1, day = parseInt(date[2]);
  }

  if (year < 1921 || year > 2020) {
    return {};
  }

  let total,
    m,
    n,
    k,
    bit,
    lunarYear,
    lunarMonth,
    lunarDay;
  let isEnd = false;
  let tmp = year;
  if (tmp < 1900) {
    tmp += 1900;
  }
  total = (tmp - 1921) * 365 + Math.floor((tmp - 1921) / 4) + lunar.monthadd[month] + day - 38;
  if (year % 4 == 0 && month > 1) {
    total++;
  }
  for (m = 0; ; m++) {
    k = (lunar.calendar[m] < 0xfff) ? 11 : 12;
    for (n = k; n >= 0; n--) {
      bit = (lunar.calendar[m] >> n) & 1;
      if (total <= 29 + bit) {
        isEnd = true;
        break;
      }
      total = total - 29 - bit;
    }
    if (isEnd) break;
  }
  lunarYear = 1921 + m;
  lunarMonth = k - n + 1;
  lunarDay = total;
  if (k == 12) {
    if (lunarMonth == Math.floor(lunar.calendar[m] / 0x10000) + 1) {
      lunarMonth = 1 - lunarMonth;
    }
    if (lunarMonth > Math.floor(lunar.calendar[m] / 0x10000) + 1) {
      lunarMonth--;
    }
  }

  return {
    lunarYear,
    lunarMonth,
    lunarDay,
  };
};

// 获取阴历年信息
const getLunarDateString = (lunarDate) => {
  if (!lunarDate.lunarDay) return;
  let data = {};
  let lunarYear = lunarDate.lunarYear;
  let lunarMonth = lunarDate.lunarMonth;
  let lunarDay = lunarDate.lunarDay;

  data.tg = lunar.tg.charAt((lunarYear - 4) % 10);
  data.dz = lunar.dz.charAt((lunarYear - 4) % 12);
  data.year = lunar.year.charAt((lunarYear - 4) % 12);
  data.month = lunarMonth < 1 ? `(闰)${lunar.month.charAt(-lunarMonth - 1)}` : lunar.month.charAt(lunarMonth - 1);

  data.day = (lunarDay < 11) ? '初' : ((lunarDay < 20) ? '十' : ((lunarDay < 30) ? '廿' : '三十'));
  if (lunarDay % 10 != 0 || lunarDay == 10) {
    data.day += lunar.number.charAt((lunarDay - 1) % 10);
  }

  return data;
};

module.exports = {
  getLunarDate: getLunarDate,           // 返回值 yyyy-MM-DD
  getLunarDateString: getLunarDateString// 返回值{day: "一",dz: "未",month: "腊",tg: "辛",year: "羊"} 
}

导入

在需要用到的页面的js中的头部导入工具代码：

var calendar = require('../../utils/calendar.js');

使用方法

阳历转农历：
var nongli = calendar.getLunarDate('2020-01-22');
返回值格式：yyyy-MM-DD

获取农历信息：
var nonglixinxi = calendar.getLunarDate(nongli);
返回值格式：{tg: "己", dz: "亥", year: "猪", month: "腊", day: "廿八"}