阴阳历转换

阳历与阴历我国通常使用的纪年方法。阳历又叫公历，阴历又叫农历。外事用阳历，以与国际接轨，内事用阴历，以合国人习惯。不过现在农历大只使用在一些节日和祭祀活动中，而公历的应用却越来越广泛。由于地球绕太阳转一周是365.2422，如果按公转一圈为一年，那么无论公历还是农历都无法非常精确的表示一年。所以农历平年十二个月，大月三十天，小月二十九天，全年354天或355天（一年中哪个月大，哪个月小，年年不同）。由于每年的天数比太阳年约差十一天，所以在十九年里设置七个闰月，有闰月的年份全年383天或384天。而阳历却比较简单，平年365天，四年一闰，闰年366天。他们表达都不如干支纪年表示准确，因为干支纪年是按照二十四节气来划分的，而二十四节又是地球公转轨道的360度按二十四份等分得来。由于农历自身的特点，所以农历大约只使用在节日或者祭祀活动中。同样由于相同的原因，公历和农历的转换比较麻烦，因为农历闰月实在太不固定了，一般是国家机构或者天文台推算一百到二百年的公历农对应历信息供人参考使用。这里使用台湾一家天文台提供的换算信息，我把他处理成数组，以供调用。该数组使用17个BIT来表示阴历每年信息。最低四个BIT表示该年闰月是闰哪个月，接下来的中间12个BIT表示每月是大月还是小月，第十七个BIT表示该年有没有闰年。转换算法也很简单，公历转农历，计算阳历某年月日到1900年的天数，然后推算出阴历哪个日期与1900相差的天数与阳历相同，两者即为同一天。农历转阴历算法同理。

#include "stdafx.h"
#include "calendar.h"
#include <stdio.h>
//使用4个BYTE存储，最高两个BYTE的最低BIT存储闰月大小，剩下两个BYTE的高十二个BIT存储大小月信息，低四个BIT存闰的月份，1900-2100
DWORD calendar::lunarInfo[]={
0x04bd8,0x04ae0,0x0a570,0x054d5,0x0d260,0x0d950,0x16554,0x056a0,0x09ad0,0x055d2,
0x04ae0,0x0a5b6,0x0a4d0,0x0d250,0x1d255,0x0b540,0x0d6a0,0x0ada2,0x095b0,0x14977,
0x04970,0x0a4b0,0x0b4b5,0x06a50,0x06d40,0x1ab54,0x02b60,0x09570,0x052f2,0x04970,
0x06566,0x0d4a0,0x0ea50,0x06e95,0x05ad0,0x02b60,0x186e3,0x092e0,0x1c8d7,0x0c950,
0x0d4a0,0x1d8a6,0x0b550,0x056a0,0x1a5b4,0x025d0,0x092d0,0x0d2b2,0x0a950,0x0b557,
0x06ca0,0x0b550,0x15355,0x04da0,0x0a5d0,0x14573,0x052d0,0x0a9a8,0x0e950,0x06aa0,
0x0aea6,0x0ab50,0x04b60,0x0aae4,0x0a570,0x05260,0x0f263,0x0d950,0x05b57,0x056a0,
0x096d0,0x04dd5,0x04ad0,0x0a4d0,0x0d4d4,0x0d250,0x0d558,0x0b540,0x0b5a0,0x195a6,
0x095b0,0x049b0,0x0a974,0x0a4b0,0x0b27a,0x06a50,0x06d40,0x0af46,0x0ab60,0x09570,
0x04af5,0x04970,0x064b0,0x074a3,0x0ea50,0x06b58,0x055c0,0x0ab60,0x096d5,0x092e0,
0x0c960,0x0d954,0x0d4a0,0x0da50,0x07552,0x056a0,0x0abb7,0x025d0,0x092d0,0x0cab5,
0x0a950,0x0b4a0,0x0baa4,0x0ad50,0x055d9,0x04ba0,0x0a5b0,0x15176,0x052b0,0x0a930,
0x07954,0x06aa0,0x0ad50,0x05b52,0x04b60,0x0a6e6,0x0a4e0,0x0d260,0x0ea65,0x0d530,
0x05aa0,0x076a3,0x096d0,0x04bd7,0x04ad0,0x0a4d0,0x1d0b6,0x0d250,0x0d520,0x0dd45,
0x0b5a0,0x056d0,0x055b2,0x049b0,0x0a577,0x0a4b0,0x0aa50,0x1b255,0x06d20,0x0ada0
/******************************************************************************/
,0x14b63,0x09370,0x049f8,0x04970,0x064b0,0x168a6,0x0ea50,0x06b20,0x1a6c4,0x0aae0,
0x092e0,0x0d2e3,0x0c960,0x0d557,0x0d4a0,0x0da50,0x05d55,0x056a0,0x0a6d0,0x055d4,
0x052d0,0x0a9b8,0x0a950,0x0b4a0,0x0b6a6,0x0ad50,0x055a0,0x0aba4,0x0a5b0,0x052b0,
0x0b273,0x06930,0x07337,0x06aa0,0x0ad50,0x14b55,0x04b60,0x0a570,0x054e4,0x0d260,
0x0e968,0x0d520,0x0daa0,0x16aa6,0x056d0,0x04ae0,0x0a9d4,0x0a4d0,0x0d150,0x0f252,
0x0d520};
UINT calendar::solarMonth[]={31,28,31,30,31,30,31,31,30,31,30,31};
//农历y年的总天数，先按小月29天算，得出日期348，加上大月多出的1天，再加上闰月天数
UINT calendar::lYearDays(UINT y)
{
UINT i, sum = 348;
for(i=0x8000; i>0x8; i>>=1)
{
sum += (lunarInfo[y-1900] & i)? 1: 0;
}
return(sum+leapDays(y));
}
//传回农历 y年闰月的天数
UINT calendar::leapDays(UINT y)
{
if(leapMonth(y))
{
return (lunarInfo[y-1900] & 0x10000)? 30: 29;
}
else
{
return 0;
}
}
// 传回农历 y年闰哪个月 1-12 , 没闰传回 0
UINT calendar::leapMonth(UINT y)
{
return lunarInfo[y-1900] & 0xf;
}
//传回农历 y年m月的总天数
UINT calendar::monthDays(UINT y,UINT m)
{
return (lunarInfo[y-1900] & (0x10000>>m))? 30: 29;
}
//获得阳历某年月日与1900年相差的天数
LONG calendar::lDaysFrom1900(myDATE date)
{
LONG days;

days=365*date.year+(date.year-1)/4-(date.year-1)/100+(date.year-1)/400-
(365*1900+(1900-1)/4-(1900-1)/100+(1900-1)/400);

for(UINT i=0;i<date.month-1;i++)
{
days+=solarMonth[i];
}
days+=date.day;
if((date.year%4==0&&date.year%100!=0)||date.year%400==0)
{
if(date.month>2)
{
days++;
}
}
return days;
}
//输入阳历日期，返回阴历日期
myDATE calendar::Lunar(myDATE date,myDATE *retdate )
{
LONG offset;
int i, leap=0, temp=0;

offset=lDaysFrom1900(date)-30;

for(i=1900; i<2050 && offset>0; i++)
{
temp = lYearDays(i);
offset -= temp;
}

if(offset<0)
{
offset += temp;
i--;
}

retdate.year = i;

leap = leapMonth(i);
bool isLeap = false;

for(i=1; i<13 && offset>0; i++)
{
if(leap>0 && i==(leap+1) && isLeap==false)
{
--i;
isLeap = true;
temp = leapDays(retdate.year);
}
else
{
temp = monthDays(retdate.year, i);
}
if(isLeap==true && i==(leap+1))
{
isLeap = false;
}
offset -= temp;
}
if(offset==0 && leap>0 && i==leap+1)
{
if(isLeap)
{
isLeap = false;
}
else
{
isLeap = true;
--i;
}
}
if(offset<=0)
{
offset += temp;
--i;
}
retdate.month = i;
retdate.day = offset ;
retdate.hour = date.hour;
retdate.isRunYue=isLeap;
return retdate;
}