C#公歷轉農歷算法

 
/// <summary>
/// LunDay 的摘要說明。
/// 用法說明
/// 直接調用即可,比較簡單
/// </summary>
public class LunDay
{
    public LunDay()
    {
        //
        // TODO: 在此處添加構造函數邏輯
        //
    }
    //天干
    private static string[] TianGan = { "甲", "乙", "丙", "丁", "戊", "己", "庚", "辛", "壬", "癸" };


//地支
private static string[] DiZhi = { "子", "丑", "寅", "卯", "辰", "巳", "午", "未", "申", "酉", "戌", "亥" };

//十二生肖
private static string[] ShengXiao = { "鼠", "牛", "虎", "兔", "龍", "蛇", "馬", "羊", "猴", "雞", "狗", "豬" };

//農歷日期
private static string[] DayName =   {"*","初一","初二","初三","初四","初五",
     "初六","初七","初八","初九","初十",
     "十一","十二","十三","十四","十五",
     "十六","十七","十八","十九","二十",
     "廿一","廿二","廿三","廿四","廿五",      
     "廿六","廿七","廿八","廿九","三十"};

//農歷月份
private static string[] MonthName = { "*", "正", "二", "三", "四", "五", "六", "七", "八", "九", "十", "十一", "臘" };

//公歷月計數天
private static int[] MonthAdd = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
//農歷數據
private static int[] LunarData = {2635,333387,1701,1748,267701,694,2391,133423,1175,396438
    ,3402,3749,331177,1453,694,201326,2350,465197,3221,3402
    ,400202,2901,1386,267611,605,2349,137515,2709,464533,1738
    ,2901,330421,1242,2651,199255,1323,529706,3733,1706,398762
    ,2741,1206,267438,2647,1318,204070,3477,461653,1386,2413
    ,330077,1197,2637,268877,3365,531109,2900,2922,398042,2395
    ,1179,267415,2635,661067,1701,1748,398772,2742,2391,330031
    ,1175,1611,200010,3749,527717,1452,2742,332397,2350,3222
    ,268949,3402,3493,133973,1386,464219,605,2349,334123,2709
    ,2890,267946,2773,592565,1210,2651,395863,1323,2707,265877};
/// <summary>
/// 獲取對應日期的農歷
/// </summary>
/// <param name="dtDay">公歷日期</param>
/// <returns></returns>
public string GetLunarCalendar(DateTime dtDay)
{
    string sYear = dtDay.Year.ToString();
    string sMonth = dtDay.Month.ToString();
    string sDay = dtDay.Day.ToString();
    int year;
    int month;
    int day;
    try
    {
        year = int.Parse(sYear);
        month = int.Parse(sMonth);
        day = int.Parse(sDay);
    }
    catch
    {
        year = DateTime.Now.Year;
        month = DateTime.Now.Month;
        day = DateTime.Now.Day;
    }

    int nTheDate;
    int nIsEnd;
    int k, m, n, nBit, i;
    string calendar = string.Empty;
    //計算到初始時間1921年2月8日的天數：1921-2-8(正月初一)
    nTheDate = (year - 1921) * 365 + (year - 1921) / 4 + day + MonthAdd[month - 1] - 38;
    if ((year % 4 == 0) && (month > 2))
        nTheDate += 1;
    //計算天干，地支，月，日
    nIsEnd = 0;
    m = 0;
    k = 0;
    n = 0;
    while (nIsEnd != 1)
    {
        if (LunarData[m] < 4095)
            k = 11;
        else
            k = 12;
        n = k;
        while (n >= 0)
        {
            //獲取LunarData[m]的第n個二進制位的值
            nBit = LunarData[m];
            for (i = 1; i < n + 1; i++)
                nBit = nBit / 2;
            nBit = nBit % 2;
            if (nTheDate <= (29 + nBit))
            {
                nIsEnd = 1;
                break;
            }
            nTheDate = nTheDate - 29 - nBit;
            n = n - 1;
        }
        if (nIsEnd == 1)
            break;
        m = m + 1;
    }
    year = 1921 + m;
    month = k - n + 1;
    day = nTheDate;
    //return year+"-"+month+"-"+day;

    #region 格式化日期顯示為三月廿四
    if (k == 12)
    {
        if (month == LunarData[m] / 65536 + 1)
            month = 1 - month;
        else if (month > LunarData[m] / 65536 + 1)
            month = month - 1;
    }

    //生肖
    calendar = ShengXiao[(year - 4) % 60 % 12].ToString() + "年 ";
    //天干
    calendar += TianGan[(year - 4) % 60 % 10].ToString();
    //地支
    calendar += DiZhi[(year - 4) % 60 % 12].ToString() + " ";

    //農歷月
    if (month < 1)
        calendar += "閏" + MonthName[-1 * month].ToString() + "月";
    else
        calendar += MonthName[month].ToString() + "月";

    //農歷日
    calendar += DayName[day].ToString() + "日";

    return calendar;

    #endregion
}

}
</pre>