程序為：
/*
西歷農歷轉換程式 黃曉鳴 1995,7,25
prototype: int calconv( struct convdate * );
struct convdate
{
int source; ==0 則輸入日期為西歷, !=0 則輸入為農歷
int solaryear; 輸出或輸入之西歷年份
int solarmonth; 西歷月
int solardate; 西歷日
int lunaryear; 輸出或輸入之農歷年份
int lunarmonth; 農歷月
int lunardate; 農歷日
int weekday; 該日為星期幾 ( 0==星期日, 1==星期一, ... )
int kan; 該日天干 ( 0==甲, 1==乙, ..., 9==癸 )
int chih; 該日地支 ( 0==子, 1==丑, ..., 11==亥 )
};
呼叫時須設定 souce 的值, 若為 0 則為西歷轉農歷, 否則為農歷轉西歷. 然後視
輸入為西歷或農歷來設定西歷或農歷的年月日. 轉換後的年月日會填入結構中( 農
歷或西歷 ), 以及該日為星期幾, 天干地支.
若函式的返回值為 0 表示沒有錯誤, 1 為輸入之年份錯誤, 2 為輸入之月份錯誤,
3 為輸入之日期錯誤.
輸入之西歷年須在 1937 - 2031 間
輸入之農歷年須在 1936 - 2030 間
若須擴充, 則增加 lunarcal[]
*/
#define firstyear 1936 /* the first year in lunarcal[] */
struct convdate
{
int source;
int solaryear;
int solarmonth;
int solardate;
int lunaryear;
int lunarmonth;
int lunardate;
int weekday;
int kan;
int chih;
};
struct taglunarcal
{
int basedays; /* 到西歷 1 月 1 日到農歷正月初一的累積日數 */
int intercalation; /* 閏月月份. 0==此年沒有閏月 */
int baseweekday; /* 此年西歷 1 月 1 日為星期幾再減 1 */
int basekanchih; /* 此年西歷 1 月 1 日之干支序號減 1 */
int monthdays[13]; /* 此農歷年每月之大小, 0==小月(29日), 1==大月(30日)*/
};
struct taglunarcal lunarcal[] = {
{ 23, 3, 2, 17, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0 }, /* 1936 */
{ 41, 0, 4, 23, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1 },
{ 30, 7, 5, 28, 1, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1 },
{ 49, 0, 6, 33, 1, 1, 0, 0, 1, 0, 0, 1, 0, 1, 0, 1, 1 },
{ 38, 0, 0, 38, 1, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1 }, /* 1940 */
{ 26, 6, 2, 44, 1, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 0 },
{ 45, 0, 3, 49, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0 },
{ 35, 0, 4, 54, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1 },
{ 24, 4, 5, 59, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 1 }, /* 1944 */
{ 43, 0, 0, 5, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1, 1 },
{ 32, 0, 1, 10, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1 },
{ 21, 2, 2, 15, 1, 1, 0, 0, 1, 0, 0, 1, 0, 1, 0, 1, 1 },
{ 40, 0, 3, 20, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 1 }, /* 1948 */
{ 28, 7, 5, 26, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1 },
{ 47, 0, 6, 31, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 1, 0, 1 },
{ 36, 0, 0, 36, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0 },
{ 26, 5, 1, 41, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1 }, /* 1952 */
{ 44, 0, 3, 47, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 1, 0, 1 },
{ 33, 0, 4, 52, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0 },
{ 23, 3, 5, 57, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 1, 1 },
{ 42, 0, 6, 2, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 1, 1 }, /* 1956 */
{ 30, 8, 1, 8, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0 },
{ 48, 0, 2, 13, 1, 1, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0 },
{ 38, 0, 3, 18, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1 },
{ 27, 6, 4, 23, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0 }, /* 1960 */
{ 45, 0, 6, 29, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0 },
{ 35, 0, 0, 34, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1 },
{ 24, 4, 1, 39, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 1, 1, 0 },
{ 43, 0, 2, 44, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 1, 1, 0 }, /* 1964 */
{ 32, 0, 4, 50, 0, 1, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1 },
{ 20, 3, 5, 55, 1, 1, 1, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0 },
{ 39, 0, 6, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 1, 0, 1, 0 },
{ 29, 7, 0, 5, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1 }, /* 1968 */
{ 47, 0, 2, 11, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1 },
{ 36, 0, 3, 16, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0 },
{ 26, 5, 4, 21, 0, 1, 0, 0, 1, 0, 1, 0, 1, 1, 1, 0, 1 },
{ 45, 0, 5, 26, 0, 1, 0, 0, 1, 0, 1, 0, 1, 1, 0, 1, 1 }, /* 1972 */
{ 33, 0, 0, 32, 1, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1 },
{ 22, 4, 1, 37, 1, 1, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1 },
{ 41, 0, 2, 42, 1, 1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1 },
{ 30, 8, 3, 47, 1, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1 }, /* 1976 */
{ 48, 0, 5, 53, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1 },
{ 37, 0, 6, 58, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1 },
{ 27, 6, 0, 3, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0 },
{ 46, 0, 1, 8, 1, 0, 0, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0 }, /* 1980 */
{ 35, 0, 3, 14, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1 },
{ 24, 4, 4, 19, 1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1 },
{ 43, 0, 5, 24, 1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1 },
{ 32, 10, 6, 29, 1, 0, 1, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1 }, /* 1984 */
{ 50, 0, 1, 35, 0, 1, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0 },
{ 39, 0, 2, 40, 0, 1, 1, 0, 1, 1, 0, 1, 0, 1, 0, 0, 1 },
{ 28, 6, 3, 45, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 0 },
{ 47, 0, 4, 50, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1 }, /* 1988 */
{ 36, 0, 6, 56, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0 },
{ 26, 5, 0, 1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1, 1 },
{ 45, 0, 1, 6, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1, 0 },
{ 34, 0, 2, 11, 0, 1, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 0 }, /* 1992 */
{ 22, 3, 4, 17, 0, 1, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0 },
{ 40, 0, 5, 22, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0 },
{ 30, 8, 6, 27, 0, 1, 1, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1 },
{ 49, 0, 0, 32, 0, 1, 0, 1, 1, 0, 1, 0, 1, 1, 0, 0, 1 }, /* 1996 */
{ 37, 0, 2, 38, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1 },
{ 27, 5, 3, 43, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 1 },
{ 46, 0, 4, 48, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1 },
{ 35, 0, 5, 53, 1, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1 }, /* 2000 */
{ 23, 4, 0, 59, 1, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1 },
{ 42, 0, 1, 4, 1, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1 },
{ 31, 0, 2, 9, 1, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 0 },
{ 21, 2, 3, 14, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1 }, /* 2004 */
{ 39, 0, 5, 20, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1 },
{ 28, 7, 6, 25, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 1 },
{ 48, 0, 0, 30, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1, 1 },
{ 37, 0, 1, 35, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1 }, /* 2008 */
{ 25, 5, 3, 41, 1, 1, 0, 0, 1, 0, 0, 1, 0, 1, 0, 1, 1 },
{ 44, 0, 4, 46, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 1 },
{ 33, 0, 5, 51, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1 },
{ 22, 4, 6, 56, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0 }, /* 2012 */
{ 40, 0, 1, 2, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0 },
{ 30, 9, 2, 7, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1 },
{ 49, 0, 3, 12, 0, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1, 0, 1 },
{ 38, 0, 4, 17, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0 }, /* 2016 */
{ 27, 6, 6, 23, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 1, 1 },
{ 46, 0, 0, 28, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 1, 0 },
{ 35, 0, 1, 33, 0, 1, 1, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0 },
{ 24, 4, 2, 38, 0, 1, 1, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1 }, /* 2020 */
{ 42, 0, 4, 44, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1 },
{ 31, 0, 5, 49, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0 },
{ 21, 2, 6, 54, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1 },
{ 40, 0, 0, 59, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1 }, /* 2024 */
{ 28, 6, 2, 5, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 1, 1, 0 },
{ 47, 0, 3, 10, 1, 0, 1, 0, 0, 1, 0, 0, 1, 1, 1, 0, 1 },
{ 36, 0, 4, 15, 1, 1, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1 },
{ 25, 5, 5, 20, 1, 1, 1, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0 }, /* 2028 */
{ 43, 0, 0, 26, 1, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1 },
{ 32, 0, 1, 31, 1, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 0 },
{ 22, 3, 2, 36, 0, 1, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0 } };
#define lastyear (firstyear+sizeof(lunarcal)/sizeof(struct taglunarcal)-1)
/* 西歷年每月之日數 */
int solarcal[12] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
/* 西歷年每月之累積日數, 平年與閏年 */
int solardays[2][14] = {
{ 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365, 396 },
{ 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366, 397 } };
/* 求此西歷年是否為閏年, 返回 0 為平年, 1 為閏年 */
int getleap( int year )
{
if ( year % 400 == 0 )
return 1;
else if ( year % 100 == 0 )
return 0;
else if ( year % 4 == 0 )
return 1;
else
return 0;
}
/* 西歷農歷轉換 */
int calconv( struct convdate *cd )
{
int leap, d, sm, y, im, l1, l2, acc, i, lm, kc;
if ( cd->source == 0 ) /* solar */
{
if ( cd->solaryear <= firstyear || cd->solaryear > lastyear )
return 1;
sm = cd->solarmonth - 1;
if ( sm < 0 || sm > 11 )
return 2;
leap = getleap( cd->solaryear );
if ( sm == 1 )
d = leap + 28;
else
d = solarcal[sm];
if ( cd->solardate < 1 || cd->solardate > d )
return 3;
y = cd->solaryear - firstyear;
acc = solardays[leap][sm] + cd->solardate;
cd->weekday = ( acc + lunarcal[y].baseweekday ) % 7;
kc = acc + lunarcal[y].basekanchih;
cd->kan = kc % 10;
cd->chih = kc % 12;
if ( acc <= lunarcal[y].basedays )
{
y--;
cd->lunaryear = cd->solaryear - 1;
leap = getleap( cd->lunaryear );
sm += 12;
acc = solardays[leap][sm] + cd->solardate;
}
else
cd->lunaryear = cd->solaryear;
l1 = lunarcal[y].basedays;
for ( i=0; i<13; i++ )
{
l2 = l1 + lunarcal[y].monthdays[i] + 29;
if ( acc <= l2 )
break;
l1 = l2;
}
cd->lunarmonth = i + 1;
cd->lunardate = acc - l1;
im = lunarcal[y].intercalation;
if ( im != 0 && cd->lunarmonth > im )
{
cd->lunarmonth--;
if ( cd->lunarmonth == im )
cd->lunarmonth = -im;
}
if ( cd->lunarmonth > 12 )
cd->lunarmonth -= 12;
}
else /* lunar */
{
if ( cd->lunaryear < firstyear || cd->lunaryear >= lastyear )
return 1;
y = cd->lunaryear - firstyear;
im = lunarcal[y].intercalation;
lm = cd->lunarmonth;
if ( lm < 0 )
{
if ( lm != -im )
return 2;
}
else if ( lm < 1 || lm > 12 )
return 2;
if ( im != 0 )
{
if ( lm > im )
lm++;
else if ( lm == -im )
lm = im + 1;
}
lm--;
if ( cd->lunardate > lunarcal[y].monthdays[lm] + 29 )
return 3;
acc = lunarcal[y].basedays;
for ( i=0; i acc += lunarcal[y].monthdays[i] + 29;
acc += cd->lunardate;
leap = getleap( cd->lunaryear );
for ( i=13; i>=0; i-- )
if ( acc > solardays[leap][i] )
break;
cd->solardate = acc - solardays[leap][i];
if ( i <= 11 )
{
cd->solaryear = cd->lunaryear;
cd->solarmonth = i + 1;
}
else
{
cd->solaryear = cd->lunaryear + 1;
cd->solarmonth = i - 11;
}
leap = getleap( cd->solaryear );
y = cd->solaryear - firstyear;
acc = solardays[leap][cd->solarmonth-1] + cd->solardate;
cd->weekday = ( acc + lunarcal[y].baseweekday ) % 7;
kc = acc + lunarcal[y].basekanchih;
cd->kan = kc % 10;
cd->chih = kc % 12;
}
return 0;
}
