萬年歷算法分析:萬年歷算法
一、 陽歷算法
具體算法見函數Void get_solar_day_date(void)，這樣陽歷日歷的星期排法就確定了。
表1：

月份 1 2 3 4 5 6 7 8 9 10 11 12
閏年 31 29 31 30 31 30 31 31 30 31 30 31
非閏年 31 28 31 30 31 30 31 31 30 31 30 31
變量定義：
Public:
Unsigned int temp_total_day;
Unsigned char gc_solar_calendar_year;
Unsigned char gc_solar_calendar_month;
Unsigned char gc_solar_calendar_date;
Unsigned char gc_lunar_calendar_year;
Unsigned char gc_lunar_calendar_month;
Unsigned char gc_lunar_calendar_date;
Unsigned char start_day_of_week；
說明：函數get_solar_day_date(void)的輸入變量：gc_solar_calendar_year和gc_solar_calendar_month
輸出變量：start_day_of_week和temp_total_day
Void get_solar_day_date(void)
{
unsigned char temp01;
/*------calculate what day is the day of the current month and year. Mon~Sun?---*/
/*條件初始化二次，減少運算數據量. temp_total_day 是int型變量*/
start_day_of_week = 2; temp_total_day = 0;calculate_temp = 1;
if(gc_solar_calendar_year > 99)
{start_day_of_week = 6;calculate_temp = 100;}
for(temp01 = calculate_temp; temp01{ if(temp01%4 == 0){start_day_of_week +=2;temp_total_day += 366; }
else {start_day_of_week +=1;temp_total_day += 365;}}
for(temp01 = 1;temp01{ switch(temp01)
{case 1,3,5,7,8,10,12: start_day_of_week +=3;temp_total_day +=31;break;
case 2: if(((gc_solar_calendar_year%4) == 0)&&(gc_solar_calendar_year != 200))
{start_day_of_week +=1; temp_total_day +=29;}
else {start_day_of_week +=0;temp_total_day +=28;} break;
case 4,6,9,11: start_day_of_week +=2; temp_total_day +=30; break;}}
start_day_of_week %=7;
/*-end of calculate what day is the day(Mon~Sun?) and total day --*/