需求来源

之前写了一篇获取农历日期的文章，【微信小程序】获取农历及星期，后来想到我这个小程序【TimeAssistant】中的“远离工作”功能模块还得优化，具体功能界面如下图

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此功能原来做法是把节假日日期固定写在代码里，这样做的话很不灵活，每年都得至少更新一次版本，如果能让这个日期动态获取，这样岂不是更好。
考虑到这里面几个节日都是跟农历相关，比如中秋、端午、春节，所以就想到写一个方法，传入农历日期获取公历日期

实战代码

核心方法

  /*** 根据农历获取阳历* @see https://blog.csdn.net/zhangjiaqianghh/article/details/115478404* @param {农历日期, 2022-01-01} lunar * @param {是否闰月, false} leapMonthFlag * @return {阳历日期, 2022-02-01} newDate*/
const getSolarByLunar = (lunar,leapMonthFlag) => {// 使用//g正则替换所有var lunarDt = lunar.replace(/-/g,'');var lunarYear = parseInt(lunarDt.substring(0, 4));var lunarMonth = parseInt(lunarDt.substring(4, 6));var lunarDay = parseInt(lunarDt.substring(6, 8));checkLunarDate(lunarYear, lunarMonth, lunarDay, leapMonthFlag);var offset = 0;for (var i = 1900; i < lunarYear; i++) {var yearDaysCount = getYearDays(i); // 求阴历某年天数offset += yearDaysCount;}var leapMonth = getLeapMonth(lunarYear);  //当年没有闰月或月份早于闰月或和闰月同名的月份  if (leapMonth == 0 || (lunarMonth < leapMonth) || (!leapMonthFlag & lunarMonth == leapMonth)) {for (var i = 1; i < lunarMonth; i++) {var tempMonthDaysCount = getMonthDays(lunarYear, i);offset += tempMonthDaysCount;}// 检查日期是否大于最大天if (lunarDay > getMonthDays(lunarYear, lunarMonth)) {console.error('不合法的农历日期！')}offset += lunarDay; // 加上当月的天数}else{console.log("当年有闰月，且月份晚于或等于闰月======" + leapMonth);//当年有闰月，且月份晚于或等于闰月for (var i = 1; i < lunarMonth; i++) {var tempMonthDaysCount = getMonthDays(lunarYear, i);offset += tempMonthDaysCount;}if (lunarMonth > leapMonth) {var temp = getLeapMonthDays(lunarYear); // 计算闰月天数offset += temp; // 加上闰月天数if (lunarDay > getMonthDays(lunarYear, lunarMonth)) {throw (new Exception("不合法的农历日期！"));}offset += lunarDay;} else {    // 如果需要计算的是闰月，则应首先加上与闰月对应的普通月的天数// 计算月为闰月var temp = getMonthDays(lunarYear, lunarMonth); // 计算非闰月天数offset += temp;if (lunarDay > getLeapMonthDays(lunarYear)) {throw (new Exception("不合法的农历日期！"));}offset += lunarDay;}}// 阳历日期计算起点var startStr = '1900-01-30';var newDate =new Date(startStr);newDate.setDate(newDate.getDate() + offset);//  console.log("测试1======" + getZeroDate(newDate) +getWeekByDate(newDate));return newDate;
}

/*** 根据阳历获取农历* @see https://www.iteye.com/blog/lixor-1190599* @param {当前日期} curDate * @returns {int数组 [1,2]} result：索引1代表天数，索引2代表月份*/
const getLunarBySolar = curDate => {var leapMonth = 0;var date = new Date('1900/1/31');// 求出当前时间和1900年1月31日相差的天数var offset = parseInt( (curDate.getTime() - date.getTime()) / 86400000 );// 用offset减去每农历年的天数，计算当天是农历第几天，i最终结果是农历的年份，offset是当年的第几天var iYear, daysOfYear = 0;for (iYear = 1900; iYear < 2100 && offset > 0; iYear++) {daysOfYear = getYearDays(iYear);offset -= daysOfYear;}if (offset < 0) {offset += daysOfYear;iYear--;}// 闰哪个月,1-12leapMonth = getLeapMonth(iYear);var leap = false; // 默认值// 用当年的天数offset,逐个减去每月（农历）的天数，求出当天是本月的第几天var iMonth, daysOfMonth = 0;for (iMonth = 1; iMonth < 13 && offset > 0; iMonth++) {// 闰月if (leapMonth > 0 && iMonth == (leapMonth + 1) && !leap) {--iMonth;leap = true;daysOfMonth = getLeapMonthDays(iYear);} elsedaysOfMonth = getMonthDays(iYear, iMonth);offset -= daysOfMonth;// 解除闰月if (leap && iMonth == (leapMonth + 1))leap = false;} // offset为0时，并且刚才计算的月份是闰月，要校正if (offset == 0 && leapMonth > 0 && iMonth == leapMonth + 1) {if (leap) {leap = false;} else {leap = true;--iMonth;}}// offset小于0时，也要校正if (offset < 0) {offset += daysOfMonth;--iMonth;}var result = [];result.push(chineseNumber[iMonth - 1]);result.push(getChinaDayString(offset + 1));return result;
}

运行效果

以下为上面两个方法实测日志图
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工具方法

1、检查农历日期是否有问题

const checkLunarDate = (lunarYear,lunarMonth,lunarDay,leapMonthFlag) =>{if(lunarYear < 1900 || lunarYear > 2100){console.error("非法年份" + lunarYear);}if(lunarMonth < 1 ||lunarMonth > 12){console.error("非法月======" + lunarMonth);}if(lunarDay < 1 ||lunarDay > 31){console.error("非法天======" + lunarDay);}//计算该年闰几月var leapMonth = getLeapMonth(lunarYear);  if (leapMonthFlag & leapMonth != lunarMonth) {//  console.error("非润月======");}
}

2，计算该年闰几月

const getLeapMonth = year =>{return (lunarInfo[year - 1900] & 0xf);
}

3，获取某闰年某月天数

  const getMonthDays = (lunarYeay, month) =>{if ((month > 31) || (month < 0)) {throw (new Exception("月份有错！"));}// 0X0FFFF[0000 {1111 1111 1111} 1111]中间12位代表12个月，1为大月，0为小月var bit = 1 << (16 - month);if (((lunarInfo[lunarYeay - 1900] & 0x0FFFF) & bit) == 0) {return 29;} else {return 30;}}

4，获取闰月天数

const getLeapMonthDays = year => {if (getLeapMonth(year) != 0) {if ((lunarInfo[year - 1900] & 0xf0000) == 0) {return 29;} else {return 30;}} else {return 0;}
}