Lua 公历转农历算法

国际通用的历法是以一个太阳回归年为周期，谓之太阳历，简称为阳历，全球公用，故亦称为公历。阳历即是公历。

中国传统的历法自夏朝始，称为夏历，是以月球绕地球一周为一月，十二月为一年，月亮号为太阴，故谓之太阴历，简称为阴历。

 夏历将太阴历配合了闰年及二十四节气，使得太阴历的年周期同步于太阳历。中国夏历其实是阴阳合历。

中国以农业立国，夏历的节气时令等与农业生产密切相关，民国建立后，通用阳历，而将传统的夏历称为农历。一般意义上讲，阴历即是农历。

在lua编程中需要用到公历转换为农历的算法，这里根据c++的算法翻译了一个，发布出来，提供给有需要的Luaer使用

该算法以1921年正月初一作为初始时间开始计算，所以早于该天的计算就不准了

算法很简单，简单修改一下可以提高运行效率，这里我比较懒，就不改了。

 

------------农历转换函数-----------
---by moodlxs(moodlxs@163.com) 2013-1-21

function GetDayOf(st)
    --天干名称
    local cTianGan = {"甲","乙","丙","丁","戊","己","庚","辛","壬","癸"}
    --地支名称
    local cDiZhi = {"子","丑","寅","卯","辰","巳","午", "未","申","酉","戌","亥"}
    --属相名称
    local cShuXiang = {"鼠","牛","虎","兔","龙","蛇", "马","羊","猴","鸡","狗","猪"}
    --农历日期名
    local cDayName =
    {
        "*","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"
    }
    --农历月份名
    local cMonName = {"*","正","二","三","四","五","六", "七","八","九","十","十一","腊"}

    --公历每月前面的天数
    local wMonthAdd = {0,31,59,90,120,151,181,212,243,273,304,334}
    -- 农历数据
    local wNongliData = {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}

    local wCurYear,wCurMonth,wCurDay;
    local nTheDate,nIsEnd,m,k,n,i,nBit;
    local szNongli, szNongliDay,szShuXiang;
    ---取当前公历年、月、日---
    wCurYear = st.year;
    wCurMonth = st.mon;
    wCurDay = st.day;
    ---计算到初始时间1921年2月8日的天数：1921-2-8(正月初一)---
    nTheDate = (wCurYear - 1921) * 365 + (wCurYear - 1921) / 4 + wCurDay + wMonthAdd[wCurMonth] - 38
    if (((wCurYear % 4) == 0) and (wCurMonth > 2)) then
        nTheDate = nTheDate + 1
    end


    --计算农历天干、地支、月、日---
    nIsEnd = 0;
    m = 0;
    while nIsEnd ~= 1 do
        if wNongliData[m+1] < 4095 then
            k = 11;
        else
            k = 12;
        end
        n = k;
        while n>=0 do
            --获取wNongliData(m)的第n个二进制位的值
            nBit = wNongliData[m+1];
            for i=1,n do
                nBit = math.floor(nBit/2);
            end

            nBit = nBit % 2;


            if nTheDate <= (29 + nBit) then
                nIsEnd = 1;
                break;
            end

            nTheDate = nTheDate - 29 - nBit;
            n = n - 1;
        end
        if nIsEnd ~= 0 then
            break;
        end
        m = m + 1;
    end

    wCurYear = 1921 + m;
    wCurMonth = k - n + 1;
    wCurDay = nTheDate;
    if k == 12 then
        if wCurMonth == wNongliData[m+1] / 65536 + 1 then
            wCurMonth = 1 - wCurMonth;
        elseif wCurMonth > wNongliData[m+1] / 65536 + 1 then
            wCurMonth = wCurMonth - 1;
        end
    end

    print('农历', wCurYear, wCurMonth, wCurDay)
    --生成农历天干、地支、属相 ==> wNongli--
    szShuXiang = cShuXiang[(((wCurYear - 4) % 60) % 12) + 1]
    szShuXiang = cShuXiang[(((wCurYear - 4) % 60) % 12) + 1];
    szNongli = szShuXiang .. '(' .. cTianGan[(((wCurYear - 4) % 60) % 10)+1] .. cDiZhi[(((wCurYear - 4) % 60) % 12) + 1] .. ')年'
    --szNongli,"%s(%s%s)年",szShuXiang,cTianGan[((wCurYear - 4) % 60) % 10],cDiZhi[((wCurYear - 4) % 60) % 12]);

    --生成农历月、日 ==> wNongliDay--*/
    if wCurMonth < 1 then
        szNongliDay =  "闰" .. cMonName[(-1 * wCurMonth) + 1]
    else
        szNongliDay = cMonName[wCurMonth+1]
    end

    szNongliDay =  szNongliDay .. "月" .. cDayName[wCurDay+1]
    return szNongli .. szNongliDay
end


function main()
    local st = {}
    st.year = 2013
    st.mon = 1
    st.day = 21
    print("" .. GetDayOf(st))
end

main()