算法查找某公历年的中国新年的公历日期

本文关键字:新年 日期 中国 查找 算法 | 更新日期: 2023-09-27 17:54:18

我正在制作一个驱动程序来计算给定时间范围内的各种假期。所以,我需要找到所有中国节日(中国新年,清明节,端午节等)的公历日期。我使用了著名的"复活节算法"来计算耶稣受难日、复活节星期一、耶稣升天日和圣灵降临星期一;然而,我对它的理解不够好,无法适应中国的历法。

我也发现过类似的问题,但他们经常从格里高利文变成中文:

月亮/月相算法

在python中计算农历/阴阳日假期

http://www.herongyang.com/year/program.html

http://www.hermetic.ch/cal_stud/ch_year.htm

最后一个链接非常有帮助,但我仍然不确定如何以一种可以帮助我的方式实现该算法。任何建议或代码将非常感激!

这是我的耶稣受难日算法:

private void GetGoodFridayOccurances(DateTime startDate, DateTime endDate,      List<ObservedHoliday> observedHolidays, StandardHoliday holiday)
    {
        for (DateTime date = startDate; date <= endDate; date = date.AddYears(1))
        {
            #region Finding the Day of Easter Algorithm
            int day, month;
            int firstTwo = date.Year / 100;
            int remainderMod = date.Year % 19;
            int pfmDate = (firstTwo - 15) / 2 + 202 - 11 * remainderMod;
            #region switches
            switch (firstTwo)
            {
                case 21:
                case 24:
                case 25:
                case 27:
                case 28:
                case 29:
                case 30:
                case 31:
                case 32:
                case 34:
                case 35:
                case 38:
                    pfmDate = pfmDate - 1;
                    break;
                case 33:
                case 36:
                case 37:
                case 39:
                case 40:
                    pfmDate = pfmDate - 2;
                    break;
            }
            #endregion
            pfmDate = pfmDate % 30;
            int tA = pfmDate + 21;
            if (pfmDate == 29)
                tA = tA - 1;
            if (pfmDate == 29 && remainderMod > 10)
                tA = tA - 1;
            //Find next sunday
            int tB = (tA - 19) % 7;
            int tC = (40 - firstTwo) % 4;
            if (tC == 3 || tC > 1)
                tC = tC + 1;
            pfmDate = date.Year % 100;
            int tD = (pfmDate + pfmDate / 4) % 7;
            int tE = ((20 - tB - tC - tD) % 7) + 1;
            day = tA + tE;
            if (day > 31)
            {
                day = day - 31;
                month = 4;
            }
            else
            {
                month = 3;
            }
            #endregion
            DateTime observed = new DateTime(date.Year, month, day).AddDays(-2);
            ObservedHoliday obsdate = new ObservedHoliday(holiday);
            if (startDate == endDate && startDate.Day == observed.Day)
            {
                obsdate.DateObserved = observed;
                observedHolidays.Add(obsdate);
            }
            else if (startDate != endDate && observed >= startDate)
            {
                obsdate.DateObserved = observed;
                observedHolidays.Add(obsdate);
            }
        }  

算法查找某公历年的中国新年的公历日期

对于中国新年,我认为这将是可行的:

using System;
using System.Globalization;
public static ( Int32 year, Int32 month, Int32 day ) GetDateOfChineseNewYear()
{
    ChineseLunisolarCalendar chinese   = new ChineseLunisolarCalendar();
    GregorianCalendar        gregorian = new GregorianCalendar();
    DateTime utcNow = DateTime.UtcNow;
    // Get Chinese New Year of current UTC date/time
    DateTime chineseNewYear = chinese.ToDateTime( utcNow.Year, 1, 1, 0, 0, 0, 0 );
    // Convert back to Gregorian (you could just query properties of `chineseNewYear` directly, but I prefer to use `GregorianCalendar` for consistency:
    Int32 year  = gregorian.GetYear( chineseNewYear );
    Int32 month = gregorian.GetMonth( chineseNewYear );
    Int32 day   = gregorian.GetDayOfMonth( chineseNewYear );
    return ( year, month, day );
}

。. NET 6支持:

现在。net 6 (终于)有了DateOnly类型(在我们已经要求它20年之后…),这可以工作:

(不幸的是。net 6的Calendar类还没有更新以支持DateOnly,但它可以直接手动处理):

private static readonly ChineseLunisolarCalendar _chineseCal   = new ChineseLunisolarCalendar();
private static readonly GregorianCalendar        _gregorianCal = new GregorianCalendar();
public static DateOnly GetGregorianDateOfChineseNewYear()
{
    return GetGregorianDateOfChineseNewYear( DateTime.UtcNow.Year );
}
public static DateOnly GetGregorianDateOfChineseNewYear( Int32 gregorianYear )
{
    // Get Chinese New Year of current UTC date/time
    DateTime chineseNewYear = _chineseCal.ToDateTime( year: gregorianYear, month: 1, day: 1, /*hms:*/ 0, 0, 0, 0 );
    // Convert back to Gregorian (you could just query properties of `chineseNewYear` directly, but I prefer to use `GregorianCalendar` for consistency:
    Int32 year  = _gregorianCal.GetYear( chineseNewYear );
    Int32 month = _gregorianCal.GetMonth( chineseNewYear );
    Int32 day   = _gregorianCal.GetDayOfMonth( chineseNewYear );
    return new DateOnly( year, month, day, _gregorianCal );
}

所以运行这个…

Console.WriteLine( "Gregorian year: {0}, Chinese New Year: {1:ddd} {1}", 2021, GetGregorianDateOfChineseNewYear( 2021 ) );
Console.WriteLine();
Console.WriteLine( "Next 10 years:" );
for( Int32 i = 2022; i < 2030; i++ )
{
    Console.WriteLine( "Gregorian year: {0}, Chinese New Year: {1:ddd} {1}", i, GetGregorianDateOfChineseNewYear( i ) );
}

…输出如下:

Gregorian year: 2021, Chinese New Year: Sat 2021-02-12
Next 10 years:
Gregorian year: 2022, Chinese New Year: Tue 2022-02-01
Gregorian year: 2023, Chinese New Year: Sun 2023-01-22
Gregorian year: 2024, Chinese New Year: Sat 2024-02-10
Gregorian year: 2025, Chinese New Year: Wed 2025-01-29
Gregorian year: 2026, Chinese New Year: Tue 2026-02-17
Gregorian year: 2027, Chinese New Year: Sat 2027-02-06
Gregorian year: 2028, Chinese New Year: Wed 2028-01-26
Gregorian year: 2029, Chinese New Year: Tue 2029-02-13
Gregorian year: 2030, Chinese New Year: Sun 2030-02-03
Gregorian year: 2031, Chinese New Year: Thu 2031-01-23

由于中国历法非常复杂(并且基于天文方面的考虑),没有一种简单的方法可以计算出在所有情况下都正确的中国新年的公历日期。(有些"经验法则"在某些年份里总是会失效。)有关基本理论,请参阅此处,Windows软件执行此操作(以及其他中国日历计算),请参阅此处