Uniapp native JS to convert the Gregorian calendar to the lunar calendar

The code idea is in the following blog , I'm just recording how I got there uniapp Used in

Native js Realize the conversion from the Gregorian calendar to the lunar calendar _xm2by The blog of -CSDN Blog _javascript Lunar calendar Native js Realize the conversion of the Gregorian calendar to the lunar calendar ：[1] 1900 - 2100 Gregorian calendar 、 The lunar calendar turns to each other Js Code https://blog.csdn.net/XuM222222/article/details/82022345

First step Find the information

Click the original link provided by me , Slip to the bottom , Click on github link

The second step Copy build lunar.js

Select all assignment , Then put it on your uniapp There are special tools in the project js In the folder of

I am because the main package of wechat applet can only 2M, So subcontracting was adopted , On the subcontracted lib Folder

  The third step   rewrite lunar.js

rewrite lunar.js, So that the method can be import

Rewriting is simple , Just at the bottom , Add the following code , namely , Every one of them function, Can be export

export default {
	sloarToLunar,
	hasLeapMonth,
	leapMonthDays,
	lunarYearDays,
	lunarYearMonths,
	getTianGan,
	getDiZhi
};

  Step four   Use sloarToLunar, Realize the conversion from the Gregorian calendar to the lunar calendar

import lunarUtil from './lib/lunar.js';

export default {
		data() {
			return {
				calendarData: '',
				},
			}
		},
		onShow() {
			const date = new Date()
			let lunar = lunarUtil.sloarToLunar(date.getFullYear(), date.getMonth() + 1, date.getDate())
			this.calendarData = lunar.lunarMonth + " month " + lunar.lunarDay + " " + lunar.lunarYear + " year "
		}
}

  Step five effect

The attachment

/*  Thinking of the code from Gregorian calendar to lunar calendar ：
1、 Set up a lunar year query table 
2、 Calculate the number of days between the input Gregorian date and the Gregorian base 
3、 Start traversing the lunar calendar query table from the lunar calendar benchmark , Calculate the number of days in each year since the lunar calendar benchmark , And subtract the number of days from each other , Determine the lunar year 
4、 The remaining difference days and the days of each lunar month are used to determine the lunar month 
5、 Use the remaining difference days to determine which day of the lunar calendar  */

//  Lunar calendar 1949-2100 Year query table 
let lunarYearArr = [
		0x0b557, //1949
		0x06ca0, 0x0b550, 0x15355, 0x04da0, 0x0a5b0, 0x14573, 0x052b0, 0x0a9a8, 0x0e950, 0x06aa0, //1950-1959
		0x0aea6, 0x0ab50, 0x04b60, 0x0aae4, 0x0a570, 0x05260, 0x0f263, 0x0d950, 0x05b57, 0x056a0, //1960-1969
		0x096d0, 0x04dd5, 0x04ad0, 0x0a4d0, 0x0d4d4, 0x0d250, 0x0d558, 0x0b540, 0x0b6a0, 0x195a6, //1970-1979
		0x095b0, 0x049b0, 0x0a974, 0x0a4b0, 0x0b27a, 0x06a50, 0x06d40, 0x0af46, 0x0ab60, 0x09570, //1980-1989
		0x04af5, 0x04970, 0x064b0, 0x074a3, 0x0ea50, 0x06b58, 0x055c0, 0x0ab60, 0x096d5, 0x092e0, //1990-1999
		0x0c960, 0x0d954, 0x0d4a0, 0x0da50, 0x07552, 0x056a0, 0x0abb7, 0x025d0, 0x092d0, 0x0cab5, //2000-2009
		0x0a950, 0x0b4a0, 0x0baa4, 0x0ad50, 0x055d9, 0x04ba0, 0x0a5b0, 0x15176, 0x052b0, 0x0a930, //2010-2019
		0x07954, 0x06aa0, 0x0ad50, 0x05b52, 0x04b60, 0x0a6e6, 0x0a4e0, 0x0d260, 0x0ea65, 0x0d530, //2020-2029
		0x05aa0, 0x076a3, 0x096d0, 0x04afb, 0x04ad0, 0x0a4d0, 0x1d0b6, 0x0d250, 0x0d520, 0x0dd45, //2030-2039
		0x0b5a0, 0x056d0, 0x055b2, 0x049b0, 0x0a577, 0x0a4b0, 0x0aa50, 0x1b255, 0x06d20, 0x0ada0, //2040-2049
		0x14b63, 0x09370, 0x049f8, 0x04970, 0x064b0, 0x168a6, 0x0ea50, 0x06b20, 0x1a6c4, 0x0aae0, //2050-2059
		0x0a2e0, 0x0d2e3, 0x0c960, 0x0d557, 0x0d4a0, 0x0da50, 0x05d55, 0x056a0, 0x0a6d0, 0x055d4, //2060-2069
		0x052d0, 0x0a9b8, 0x0a950, 0x0b4a0, 0x0b6a6, 0x0ad50, 0x055a0, 0x0aba4, 0x0a5b0, 0x052b0, //2070-2079
		0x0b273, 0x06930, 0x07337, 0x06aa0, 0x0ad50, 0x14b55, 0x04b60, 0x0a570, 0x054e4, 0x0d160, //2080-2089
		0x0e968, 0x0d520, 0x0daa0, 0x16aa6, 0x056d0, 0x04ae0, 0x0a9d4, 0x0a2d0, 0x0d150, 0x0f252, //2090-2099
		0x0d520 //2100
	],
	lunarMonth = [' just ', ' Two ', ' 3、 ... and ', ' Four ', ' 5、 ... and ', ' 6、 ... and ', ' 7、 ... and ', ' 8、 ... and ', ' Nine ', ' Ten ', ' In the winter ', ' Wax '],
	lunarDay = [' One ', ' Two ', ' 3、 ... and ', ' Four ', ' 5、 ... and ', ' 6、 ... and ', ' 7、 ... and ', ' 8、 ... and ', ' Nine ', ' Ten ', ' first ', ' Twenty '],
	tianGan = [' nail ', ' B ', ' C ', ' Ding ', ' E ', ' Oneself ', ' Geng ', ' simba ', ' Ren ', ' Dec. '],
	diZhi = [' Son ', ' ugly ', ' Yin ', ' Mao ', ' Chen" ', ' Already ', ' Noon ', ' not ', ' Shen ', ' Unitary ', ' Xu ', ' Hai '];

//  Gregorian to lunar functions 
function sloarToLunar(sy, sm, sd) {

	//  The entered month minus 1 Handle 
	sm -= 1;

	//  Calculate the days difference from the Gregorian calendar benchmark 
	// Date.UTC() Returns the distance from the Gregorian calendar 1970 year 1 month 1 Milliseconds per day , The incoming month needs to be subtracted 1
	let daySpan = (Date.UTC(sy, sm, sd) - Date.UTC(1949, 0, 29)) / (24 * 60 * 60 * 1000) + 1;
	let ly, lm, ld;
	//  Determine the lunar year of the output 
	for (let j = 0; j < lunarYearArr.length; j++) {
		daySpan -= lunarYearDays(lunarYearArr[j]);
		if (daySpan <= 0) {
			ly = 1949 + j;
			//  Get the remaining days after the lunar year is determined 
			daySpan += lunarYearDays(lunarYearArr[j]);
			break
		}
	}

	//  Determine the lunar month for output 
	for (let k = 0; k < lunarYearMonths(lunarYearArr[ly - 1949]).length; k++) {
		daySpan -= lunarYearMonths(lunarYearArr[ly - 1949])[k];
		if (daySpan <= 0) {
			//  When there are leap months , The array length of the month will become 13, therefore , When the leap month is less than or equal to k when ,lm No need to add 1
			if (hasLeapMonth(lunarYearArr[ly - 1949]) && hasLeapMonth(lunarYearArr[ly - 1949]) <= k) {
				if (hasLeapMonth(lunarYearArr[ly - 1949]) < k) {
					lm = k;
				} else if (hasLeapMonth(lunarYearArr[ly - 1949]) === k) {
					lm = ' Leap ' + k;
				} else {
					lm = k + 1;
				}
			} else {
				lm = k + 1;
			}
			//  Get the remaining days after the lunar month is determined 
			daySpan += lunarYearMonths(lunarYearArr[ly - 1949])[k];
			break
		}
	}

	//  Determine which day of the lunar calendar to output 
	ld = daySpan;

	//  Convert the calculated lunar month into Chinese character month , A leap month needs to be preceded by a leap word 
	if (hasLeapMonth(lunarYearArr[ly - 1949]) && (typeof(lm) === 'string' && lm.indexOf(' Leap ') > -1)) {
		lm = ` Leap ${lunarMonth[/\d/.exec(lm) - 1]}`
	} else {
		lm = lunarMonth[lm - 1];
	}

	//  Convert the calculated lunar year to the year of heavenly stems and Earthly Branches 
	ly = getTianGan(ly) + getDiZhi(ly);

	//  Convert the calculated lunar calendar days into Chinese characters 
	if (ld < 11) {
		ld = `${lunarDay[10]}${lunarDay[ld-1]}`
	} else if (ld > 10 && ld < 20) {
		ld = `${lunarDay[9]}${lunarDay[ld-11]}`
	} else if (ld === 20) {
		ld = `${lunarDay[1]}${lunarDay[9]}`
	} else if (ld > 20 && ld < 30) {
		ld = `${lunarDay[11]}${lunarDay[ld-21]}`
	} else if (ld === 30) {
		ld = `${lunarDay[2]}${lunarDay[9]}`
	}

	console.log(ly, lm, ld);

	return {
		lunarYear: ly,
		lunarMonth: lm,
		lunarDay: ld,
	}
}

//  Calculate whether there are leap months in the lunar year , The parameter is used to store the Chinese lunar year 16 Base number 
//  The lunar year information is 16 Base store , among 16 The last of the hexadecimal 1 Bits can be used to determine whether there is a leap month 
function hasLeapMonth(ly) {
	//  obtain 16 The last of the hexadecimal 1 position , Need to use & And operators 
	if (ly & 0xf) {
		return ly & 0xf
	} else {
		return false
	}
}

//  If there is a leap month , Calculate the number of leap months in the lunar calendar , The parameter is used to store the Chinese lunar year 16 Base number 
//  The lunar year information is 16 Base store , among 16 Hexadecimal th 1 position （0x With the exception of ） It can be used to indicate whether a leap month is a big month or a small month 
function leapMonthDays(ly) {
	if (hasLeapMonth(ly)) {
		//  obtain 16 Hexadecimal th 1 position （0x With the exception of ）
		return (ly & 0xf0000) ? 30 : 29
	} else {
		return 0
	}
}

//  Calculate the total number of days in a lunar year , The parameter is used to store the Chinese lunar year 16 Base number 
//  The lunar year information is 16 Base store , among 16 Hexadecimal th 2-4 position （0x With the exception of ） It can be used to indicate whether a normal month is a big month or a small month 
function lunarYearDays(ly) {
	let totalDays = 0;

	//  Get the number of days in a normal month , Sum up 
	//  obtain 16 Hexadecimal th 2-4 position , Need to use >> Shift Operators 
	for (let i = 0x8000; i > 0x8; i >>= 1) {
		let monthDays = (ly & i) ? 30 : 29;
		totalDays += monthDays;
	}
	//  If there is a leap month , You need to add the number of days of leap month to 
	if (hasLeapMonth(ly)) {
		totalDays += leapMonthDays(ly);
	}

	return totalDays
}

//  Get the days of each month in the lunar calendar 
//  Parameters need to be passed in 16 Decimal value 
function lunarYearMonths(ly) {
	let monthArr = [];

	//  Get the number of days in a normal month , To add to monthArr Array 
	//  obtain 16 Hexadecimal th 2-4 position , Need to use >> Shift Operators 
	for (let i = 0x8000; i > 0x8; i >>= 1) {
		monthArr.push((ly & i) ? 30 : 29);
	}
	//  If there is a leap month , You need to add the number of days of leap month to 
	if (hasLeapMonth(ly)) {
		monthArr.splice(hasLeapMonth(ly), 0, leapMonthDays(ly));
	}

	return monthArr
}

//  Convert the lunar year to tiangan , The parameter is lunar year 
function getTianGan(ly) {
	let tianGanKey = (ly - 3) % 10;
	if (tianGanKey === 0) tianGanKey = 10;
	return tianGan[tianGanKey - 1]
}

//  Turn the lunar year into a local branch , The parameter is lunar year 
function getDiZhi(ly) {
	let diZhiKey = (ly - 3) % 12;
	if (diZhiKey === 0) diZhiKey = 12;
	return diZhi[diZhiKey - 1]
}

export default {
	sloarToLunar,
	hasLeapMonth,
	leapMonthDays,
	lunarYearDays,
	lunarYearMonths,
	getTianGan,
	getDiZhi
};