中国年历算法和程式

中国年历算法和程式 

本文摘自“和荣笔记 - 中国农历二百年算法及年历”

中国公历算法

中国公历算法不是太难，关键是星期值的确定。这里给出了简单算法： 

中国农历算法

根公历相比，中国农历的算法相当复杂。我在网上找的算法之中，eleworld.com 的算法是最好的一个。这个算法使用了大量的数据来确定农历月份和节气的分部，它仅实用于公历 1901 年到 2100 年之间的 200 年。 

中国农历计算程式

跟据 eleworld.com 提供的算法，我写了下面这个程式： 
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/**
 * ChineseCalendarGB.java
 * Copyright (c) 1997-2002 by Dr. Herong Yang. http://www.herongyang.com/
 * 中国农历算法 - 实用于公历 1901 年至 2100 年之间的 200 年 
 */
import java.text.*;
import java.util.*;
class ChineseCalendarGB {
   private int gregorianYear;
   private int gregorianMonth;
   private int gregorianDate;
   private boolean isGregorianLeap;
   private int dayOfYear;
   private int dayOfWeek; // 周日一星期的第一天
   private int chineseYear;
   private int chineseMonth; // 负数表示闰月
   private int chineseDate;
   private int sectionalTerm;
   private int principleTerm;
   private static char[] daysInGregorianMonth = 
      {31,28,31,30,31,30,31,31,30,31,30,31};
   private static String[] stemNames =
      {"甲","乙","丙","丁","戊","己","庚","辛","壬","癸"};
   private static String[] branchNames =
      {"子","丑","寅","卯","辰","巳","午","未","申","酉","戌","亥"};
   private static String[] animalNames =
      {"鼠","牛","虎","兔","龙","蛇","马","羊","猴","鸡","狗","猪"};
   public static void main(String[] arg) {
      ChineseCalendarGB c = new ChineseCalendarGB();
      String cmd = "day";
      int y = 1901;
      int m = 1;
      int d = 1;
      if (arg.length>0) cmd = arg[0];
      if (arg.length>1) y = Integer.parseInt(arg[1]);
      if (arg.length>2) m = Integer.parseInt(arg[2]);
      if (arg.length>3) d = Integer.parseInt(arg[3]);
      c.setGregorian(y,m,d);
      c.computeChineseFields();
      c.computeSolarTerms();
      if (cmd.equalsIgnoreCase("year")) {
         String[] t = c.getYearTable();
         for (int i=0; i      } else if (cmd.equalsIgnoreCase("month")) {
         String[] t = c.getMonthTable();
         for (int i=0; i      } else {
         System.out.println(c.toString());
      }
   }
   public ChineseCalendarGB() {
      setGregorian(1901,1,1);
   }
   public void setGregorian(int y, int m, int d) {
      gregorianYear = y;
      gregorianMonth = m;
      gregorianDate = d;
      isGregorianLeap = isGregorianLeapYear(y);
      dayOfYear = dayOfYear(y,m,d);
      dayOfWeek = dayOfWeek(y,m,d);
      chineseYear = 0;
      chineseMonth = 0;
      chineseDate = 0;
      sectionalTerm = 0;
      principleTerm = 0;
   }
   public static boolean isGregorianLeapYear(int year) {
      boolean isLeap = false;
      if (year%4==0) isLeap = true;
      if (year%100==0) isLeap = false;
      if (year%400==0) isLeap = true;
      return isLeap;
   }
   public static int daysInGregorianMonth(int y, int m) {
      int d = daysInGregorianMonth[m-1];
      if (m==2 && isGregorianLeapYear(y)) d++; // 公历闰年二月多一天
      return d;
   }
   public static int dayOfYear(int y, int m, int d) {
      int c = 0;
      for (int i=1; i         c = c + daysInGregorianMonth(y,i);
      }
      c = c + d;
      return c;      
   }
   public static int dayOfWeek(int y, int m, int d) {
      int w = 1; // 公历一年一月一日是星期一，所以起始值为星期日
      y = (y-1)%400 + 1; // 公历星期值分部 400 年循环一次
      int ly = (y-1)/4; // 闰年次数
      ly = ly - (y-1)/100;
      ly = ly + (y-1)/400;
      int ry = y - 1 - ly; // 常年次数
      w = w + ry; // 常年星期值增一
      w = w + 2*ly; // 闰年星期值增二
      w = w + dayOfYear(y,m,d); 
      w = (w-1)%7 + 1;
      return w;
   }
   private static char[] chineseMonths = { 
   // 农历月份大小压缩表，两个字节表示一年。两个字节共十六个二进制位数， 
   // 前四个位数表示闰月月份，后十二个位数表示十二个农历月份的大小。
   0x00,0x04,0xad,0x08,0x5a,0x01,0xd5,0x54,0xb4,0x09,0x64,0x05,0x59,0x45,
   0x95,0x0a,0xa6,0x04,0x55,0x24,0xad,0x08,0x5a,0x62,0xda,0x04,0xb4,0x05,
   0xb4,0x55,0x52,0x0d,0x94,0x0a,0x4a,0x2a,0x56,0x02,0x6d,0x71,0x6d,0x01,
   0xda,0x02,0xd2,0x52,0xa9,0x05,0x49,0x0d,0x2a,0x45,0x2b,0x09,0x56,0x01,
   0xb5,0x20,0x6d,0x01,0x59,0x69,0xd4,0x0a,0xa8,0x05,0xa9,0x56,0xa5,0x04,
   0x2b,0x09,0x9e,0x38,0xb6,0x08,0xec,0x74,0x6c,0x05,0xd4,0x0a,0xe4,0x6a,
   0x52,0x05,0x95,0x0a,0x5a,0x42,0x5b,0x04,0xb6,0x04,0xb4,0x22,0x6a,0x05,
   0x52,0x75,0xc9,0x0a,0x52,0x05,0x35,0x55,0x4d,0x0a,0x5a,0x02,0x5d,0x31,
   0xb5,0x02,0x6a,0x8a,0x68,0x05,0xa9,0x0a,0x8a,0x6a,0x2a,0x05,0x2d,0x09,
   0xaa,0x48,0x5a,0x01,0xb5,0x09,0xb0,0x39,0x64,0x05,0x25,0x75,0x95,0x0a,
   0x96,0x04,0x4d,0x54,0xad,0x04,0xda,0x04,0xd4,0x44,0xb4,0x05,0x54,0x85,
   0x52,0x0d,0x92,0x0a,0x56,0x6a,0x56,0x02,0x6d,0x02,0x6a,0x41,0xda,0x02,
   0xb2,0xa1,0xa9,0x05,0x49,0x0d,0x0a,0x6d,0x2a,0x09,0x56,0x01,0xad,0x50,
   0x6d,0x01,0xd9,0x02,0xd1,0x3a,0xa8,0x05,0x29,0x85,0xa5,0x0c,0x2a,0x09,
   0x96,0x54,0xb6,0x08,0x6c,0x09,0x64,0x45,0xd4,0x0a,0xa4,0x05,0x51,0x25,
   0x95,0x0a,0x2a,0x72,0x5b,0x04,0xb6,0x04,0xac,0x52,0x6a,0x05,0xd2,0x0a,
   0xa2,0x4a,0x4a,0x05,0x55,0x94,0x2d,0x0a,0x5a,0x02,0x75,0x61,0xb5,0x02,
   0x6a,0x03,0x61,0x45,0xa9,0x0a,0x4a,0x05,0x25,0x25,0x2d,0x09,0x9a,0x68,
   0xda,0x08,0xb4,0x09,0xa8,0x59,0x54,0x03,0xa5,0x0a,0x91,0x3a,0x96,0x04,
   0xad,0xb0,0xad,0x04,0xda,0x04,0xf4,0x62,0xb4,0x05,0x54,0x0b,0x44,0x5d,
   0x52,0x0a,0x95,0x04,0x55,0x22,0x6d,0x02,0x5a,0x71,0xda,0x02,0xaa,0x05,
   0xb2,0x55,0x49,0x0b,0x4a,0x0a,0x2d,0x39,0x36,0x01,0x6d,0x80,0x6d,0x01,
   0xd9,0x02,0xe9,0x6a,0xa8,0x05,0x29,0x0b,0x9a,0x4c,0xaa,0x08,0xb6,0x08,
   0xb4,0x38,0x6c,0x09,0x54,0x75,0xd4,0x0a,0xa4,0x05,0x45,0x55,0x95,0x0a,
   0x9a,0x04,0x55,0x44,0xb5,0x04,0x6a,0x82,0x6a,0x05,0xd2,0x0a,0x92,0x6a,
   0x4a,0x05,0x55,0x0a,0x2a,0x4a,0x5a,0x02,0xb5,0x02,0xb2,0x31,0x69,0x03,
   0x31,0x73,0xa9,0x0a,0x4a,0x05,0x2d,0x55,0x2d,0x09,0x5a,0x01,0xd5,0x48,
   0xb4,0x09,0x68,0x89,0x54,0x0b,0xa4,0x0a,0xa5,0x6a,0x95,0x04,0xad,0x08,
   0x6a,0x44,0xda,0x04,0x74,0x05,0xb0,0x25,0x54,0x03
   };
   // 初始日，公历农历对应日期：
   // 公历 1901 年 1 月 1 日，对应农历 4598 年 11 月 11 日
   private static int baseYear = 1901;
   private static int baseMonth = 1;
   private static int baseDate = 1;
   private static int baseIndex = 0;
   private static int baseChineseYear = 4598-1;
   private static int baseChineseMonth = 11;
   private static int baseChineseDate = 11;
   public int computeChineseFields() {
      if (gregorianYear<1901 || gregorianYear>2100) return 1;
      int startYear = baseYear;
      int startMonth = baseMonth;
      int startDate = baseDate;      
      chineseYear = baseChineseYear; 
      chineseMonth = baseChineseMonth;
      chineseDate = baseChineseDate;
      // 第二个对应日，用以提高计算效率
      // 公历 2000 年 1 月 1 日，对应农历 4697 年 11 月 25 日
      if (gregorianYear >= 2000) {
         startYear = baseYear + 99;
         startMonth = 1;
         startDate = 1;
         chineseYear = baseChineseYear + 99;
         chineseMonth = 11;
         chineseDate = 25;
      }
      int daysDiff = 0;
      for (int i=startYear; i         daysDiff += 365;
         if (isGregorianLeapYear(i)) daysDiff += 1; // leap year
      }
      for (int i=startMonth; i         daysDiff += daysInGregorianMonth(gregorianYear,i);
      }
      daysDiff += gregorianDate - startDate;
      
      chineseDate += daysDiff;
      int lastDate = daysInChineseMonth(chineseYear, chineseMonth);
      int nextMonth = nextChineseMonth(chineseYear, chineseMonth);
      while (chineseDate>lastDate) {
         if (Math.abs(nextMonth)         chineseMonth = nextMonth;
         chineseDate -= lastDate;
         lastDate = daysInChineseMonth(chineseYear, chineseMonth);
         nextMonth = nextChineseMonth(chineseYear, chineseMonth);
      }
      return 0;
   }
   private static int[] bigLeapMonthYears = {
      // 大闰月的闰年年份
        6, 14, 19, 25, 33, 36, 38, 41, 44, 52, 
       55, 79,117,136,147,150,155,158,185,193
      };
   public static int daysInChineseMonth(int y, int m) {
      // 注意：闰月 m < 0
      int index = y - baseChineseYear + baseIndex;
      int v = 0;
      int l = 0;
      int d = 30;
      if (1<=m && m<=8) {
         v = chineseMonths[2*index];
         l = m - 1;
         if ( ((v>>l)&0x01)==1 ) d = 29;
      } else if (9<=m && m<=12) {
         v = chineseMonths[2*index+1];
         l = m - 9;
         if ( ((v>>l)&0x01)==1 ) d = 29;
      } else {
         v = chineseMonths[2*index+1];
         v = (v>>4)&0x0F;
         if (v!=Math.abs(m)) {
            d = 0;
         } else {
            d = 29; 
            for (int i=0; i               if (bigLeapMonthYears[i]==index) {
                  d = 30;
                  break;
               }
            }
         }
      }
      return d;
   }
   public static int nextChineseMonth(int y, int m) {
      int n = Math.abs(m) + 1;
      if (m>0) {
         int index = y - baseChineseYear + baseIndex;
         int v = chineseMonths[2*index+1];
         v = (v>>4)&0x0F;
         if (v==m) n = -m;
      }
      if (n==13) n = 1;
      return n;
   }
   private static char[][] sectionalTermMap = {
   {7,6,6,6,6,6,6,6,6,5,6,6,6,5,5,6,6,5,5,5,5,5,5,5,5,4,5,5},  
   {5,4,5,5,5,4,4,5,5,4,4,4,4,4,4,4,4,3,4,4,4,3,3,4,4,3,3,3},  
   {6,6,6,7,6,6,6,6,5,6,6,6,5,5,6,6,5,5,5,6,5,5,5,5,4,5,5,5,5},
   {5,5,6,6,5,5,5,6,5,5,5,5,4,5,5,5,4,4,5,5,4,4,4,5,4,4,4,4,5},
   {6,6,6,7,6,6,6,6,5,6,6,6,5,5,6,6,5,5,5,6,5,5,5,5,4,5,5,5,5},
   {6,6,7,7,6,6,6,7,6,6,6,6,5,6,6,6,5,5,6,6,5,5,5,6,5,5,5,5,4,5,5,5,5},
   {7,8,8,8,7,7,8,8,7,7,7,8,7,7,7,7,6,7,7,7,6,6,7,7,6,6,6,7,7},
   {8,8,8,9,8,8,8,8,7,8,8,8,7,7,8,8,7,7,7,8,7,7,7,7,6,7,7,7,6,6,7,7,7},
   {8,8,8,9,8,8,8,8,7,8,8,8,7,7,8,8,7,7,7,8,7,7,7,7,6,7,7,7,7},
   {9,9,9,9,8,9,9,9,8,8,9,9,8,8,8,9,8,8,8,8,7,8,8,8,7,7,8,8,8},
   {8,8,8,8,7,8,8,8,7,7,8,8,7,7,7,8,7,7,7,7,6,7,7,7,6,6,7,7,7},
   {7,8,8,8,7,7,8,8,7,7,7,8,7,7,7,7,6,7,7,7,6,6,7,7,6,6,6,7,7} 
   }; 
   private static char[][] sectionalTermYear = {
   {13,49,85,117,149,185,201,250,250},
   {13,45,81,117,149,185,201,250,250},
   {13,48,84,112,148,184,200,201,250},
   {13,45,76,108,140,172,200,201,250},
   {13,44,72,104,132,168,200,201,250},
   {5 ,33,68,96 ,124,152,188,200,201},
   {29,57,85,120,148,176,200,201,250},
   {13,48,76,104,132,168,196,200,201},
   {25,60,88,120,148,184,200,201,250},
   {16,44,76,108,144,172,200,201,250},
   {28,60,92,124,160,192,200,201,250},
   {17,53,85,124,156,188,200,201,250} 
   };
   private static char[][] principleTermMap = {
   {21,21,21,21,21,20,21,21,21,20,20,21,21,20,20,20,20,20,20,20,20,19,
      20,20,20,19,19,20},
   {20,19,19,20,20,19,19,19,19,19,19,19,19,18,19,19,19,18,18,19,19,18,
      18,18,18,18,18,18},
   {21,21,21,22,21,21,21,21,20,21,21,21,20,20,21,21,20,20,20,21,20,20,
      20,20,19,20,20,20,20},
   {20,21,21,21,20,20,21,21,20,20,20,21,20,20,20,20,19,20,20,20,19,19,
      20,20,19,19,19,20,20},
   {21,22,22,22,21,21,22,22,21,21,21,22,21,21,21,21,20,21,21,21,20,20,
      21,21,20,20,20,21,21},
   {22,22,22,22,21,22,22,22,21,21,22,22,21,21,21,22,21,21,21,21,20,21,
      21,21,20,20,21,21,21},
   {23,23,24,24,23,23,23,24,23,23,23,23,22,23,23,23,22,22,23,23,22,22,
      22,23,22,22,22,22,23},
   {23,24,24,24,23,23,24,24,23,23,23,24,23,23,23,23,22,23,23,23,22,22,
      23,23,22,22,22,23,23},
   {23,24,24,24,23,23,24,24,23,23,23,24,23,23,23,23,22,23,23,23,22,22,
      23,23,22,22,22,23,23},
   {24,24,24,24,23,24,24,24,23,23,24,24,23,23,23,24,23,23,23,23,22,23,
      23,23,22,22,23,23,23},
   {23,23,23,23,22,23,23,23,22,22,23,23,22,22,22,23,22,22,22,22,21,22,
      22,22,21,21,22,22,22},
   {22,22,23,23,22,22,22,23,22,22,22,22,21,22,22,22,21,21,22,22,21,21,
      21,22,21,21,21,21,22}
   };
   private static char[][] principleTermYear = {
   {13,45,81,113,149,185,201},    
   {21,57,93,125,161,193,201},    
   {21,56,88,120,152,188,200,201},
   {21,49,81,116,144,176,200,201},
   {17,49,77,112,140,168,200,201},
   {28,60,88,116,148,180,200,201},
   {25,53,84,112,144,172,200,201},
   {29,57,89,120,148,180,200,201},
   {17,45,73,108,140,168,200,201},
   {28,60,92,124,160,192,200,201},
   {16,44,80,112,148,180,200,201},
   {17,53,88,120,156,188,200,201} 
   };
   public int computeSolarTerms() {
      if (gregorianYear<1901 || gregorianYear>2100) return 1;
      sectionalTerm = sectionalTerm(gregorianYear, gregorianMonth);
      principleTerm = principleTerm(gregorianYear, gregorianMonth);
      return 0;
   }
   public static int sectionalTerm(int y, int m) {
      if (y<1901 || y>2100) return 0;
      int index = 0;
      int ry = y-baseYear+1;
      while (ry>=sectionalTermYear[m-1][index]) index++;
      int term = sectionalTermMap[m-1][4*index+ry%4];
      if ((ry == 121)&&(m == 4)) term = 5;
      if ((ry == 132)&&(m == 4)) term = 5;
      if ((ry == 194)&&(m == 6)) term = 6;
      return term;
   }
   public static int principleTerm(int y, int m) {
      if (y<1901 || y>2100) return 0;
      int index = 0;
      int ry = y-baseYear+1;
      while (ry>=principleTermYear[m-1][index]) index++;
      int term = principleTermMap[m-1][4*index+ry%4];
      if ((ry == 171)&&(m == 3)) term = 21;
      if ((ry == 181)&&(m == 5)) term = 21;
      return term;
   }
   public String toString() {
      StringBuffer buf = new StringBuffer();
      buf.append("Gregorian Year: "+gregorianYear+"/n");
      buf.append("Gregorian Month: "+gregorianMonth+"/n");
      buf.append("Gregorian Date: "+gregorianDate+"/n");
      buf.append("Is Leap Year: "+isGregorianLeap+"/n");
      buf.append("Day of Year: "+dayOfYear+"/n");
      buf.append("Day of Week: "+dayOfWeek+"/n");
      buf.append("Chinese Year: "+chineseYear+"/n");
      buf.append("Heavenly Stem: "+((chineseYear-1)%10)+"/n");
      buf.append("Earthly Branch: "+((chineseYear-1)%12)+"/n");
      buf.append("Chinese Month: "+chineseMonth+"/n");
      buf.append("Chinese Date: "+chineseDate+"/n");
      buf.append("Sectional Term: "+sectionalTerm+"/n");
      buf.append("Principle Term: "+principleTerm+"/n");
      return buf.toString();
   }
   public String[] getYearTable() {
      setGregorian(gregorianYear,1,1);
      computeChineseFields();
      computeSolarTerms();
      String[] table = new String[58]; // 6*9 + 4
      table[0] = getTextLine(27, "公历年历："+gregorianYear);
      table[1] = getTextLine(27, "农历年历："+(chineseYear+1)
         + " ("+stemNames[(chineseYear+1-1)%10]
         + branchNames[(chineseYear+1-1)%12]
         + " - "+animalNames[(chineseYear+1-1)%12]+"年)");
      int ln = 2;
      String blank  = "                                         "
              +"  " + "                                         ";
      String[] mLeft = null;
      String[] mRight = null;
      for (int i=1; i<=6; i++) {
         table[ln] = blank;
         ln++;
         mLeft = getMonthTable();
         mRight = getMonthTable();
         for (int j=0; j            String line = mLeft[j] + "  " + mRight[j];
            table[ln] = line;
            ln++;
         }
      }
      table[ln] = blank;
      ln++;
      table[ln] = getTextLine(0,
         "##/## - 公历日期/农历日期，(*)#月 - (闰)农历月第一天");
      ln++;
      return table;
   }
   public static String getTextLine(int s, String t) {
      String str  = "                                         "
              +"  " + "                                         ";
      if (t!=null && s         str = str.substring(0,s) + t + str.substring(s+t.length());
      return str;
   }
   private static String[] monthNames =
      {"一","二","三","四","五","六","七","八","九","十","十一","十二"};
   public String[] getMonthTable() {
      setGregorian(gregorianYear,gregorianMonth,1);
      computeChineseFields();
      computeSolarTerms();
      String[] table = new String[8]; 
      String title  = null;
      if (gregorianMonth<11) title  = "                   ";
      else title  = "                 ";
      title = title + monthNames[gregorianMonth-1] + "月"
                    + "                   ";
      String header = "   日    一    二    三    四    五    六 ";
      String blank  = "                                          ";
      table[0] = title;
      table[1] = header;
      int wk = 2;
      String line = "";
      for (int i=1; i         line += "     " + ' ';
      }
      int days = daysInGregorianMonth(gregorianYear,gregorianMonth);
      for (int i=gregorianDate; i<=days; i++) {
         line += getDateString() + ' ';
         rollUpOneDay();
         if (dayOfWeek==1) {
            table[wk] = line;
            line = "";
            wk++;
         }
      }
      for (int i=dayOfWeek; i<=7; i++) {
         line += "     " + ' ';
      }
      table[wk] = line;
      for (int i=wk+1; i         table[i] = blank;
      }
      for (int i=0; i         table[i] = table[i].substring(0,table[i].length()-1);
      }
      
      return table;
   }
   private static String[] chineseMonthNames =
      {"正","二","三","四","五","六","七","八","九","十","冬","腊"};
   private static String[] principleTermNames =
      {"雨水","春分","谷雨","夏满","夏至","大暑","处暑","秋分","霜降", 
       "小雪","冬至","大寒"};
   private static String[] sectionalTermNames =
      {"立春","惊蛰","清明","立夏","芒种","小暑","立秋","白露","寒露",
       "立冬","大雪","小寒"};
   public String getDateString() {
      String str = "*  /  ";
      String gm = String.valueOf(gregorianMonth);
      if (gm.length()==1) gm = ' ' + gm;
      String cm = String.valueOf(Math.abs(chineseMonth));
      if (cm.length()==1) cm = ' ' + cm;
      String gd = String.valueOf(gregorianDate);
      if (gd.length()==1) gd = ' ' + gd;
      String cd = String.valueOf(chineseDate);
      if (cd.length()==1) cd = ' ' + cd;
      if (gregorianDate==sectionalTerm) {
         str = " "+sectionalTermNames[gregorianMonth-1];
      } else if (gregorianDate==principleTerm) {
         str = " "+principleTermNames[gregorianMonth-1];
      } else if (chineseDate==1 && chineseMonth>0) {
           str = " "+chineseMonthNames[chineseMonth-1]+"月";
      } else if (chineseDate==1 && chineseMonth<0) {
           str = "*"+chineseMonthNames[-chineseMonth-1]+"月";
      } else {
           str = gd+'/'+cd;
      }
      return str;
   }
   public int rollUpOneDay() {
      dayOfWeek = dayOfWeek%7 + 1;
      dayOfYear++;
      gregorianDate++;
      int days = daysInGregorianMonth(gregorianYear,gregorianMonth); 
      if (gregorianDate>days) {
         gregorianDate = 1;
         gregorianMonth++;
         if (gregorianMonth>12) {
            gregorianMonth = 1;
            gregorianYear++;
            dayOfYear = 1;
            isGregorianLeap = isGregorianLeapYear(gregorianYear);
         }
         sectionalTerm = sectionalTerm(gregorianYear,gregorianMonth);
         principleTerm = principleTerm(gregorianYear,gregorianMonth);
      }
      chineseDate++;
      days = daysInChineseMonth(chineseYear,chineseMonth);
      if (chineseDate>days) {
         chineseDate = 1;
         chineseMonth = nextChineseMonth(chineseYear,chineseMonth);
         if (chineseMonth==1) chineseYear++;
      }
      return 0;
   }
}

[/HTML]

中国二百年年历 1901 年至 2100 年

我用上面这个程式制作了二百年年历，1901 年至 2100 年，全部收录在这本书中。 

年历格式说明： 

农历日期列在公历日期后面。 
节气用节气名称标明。 
农历每月第一天用月份名称标明。 
例如，2000 年一月的表达格式如下： 
[HTML]

                   一月                  
   日    一    二    三    四    五    六
                                     1/25
 2/26  3/27  4/28  5/29  立春  腊月  8/ 2
 9/ 3 10/ 4 11/ 5 12/ 6 13/ 7 14/ 8 15/ 9
16/10 17/11 18/12 19/13 20/14  雨水 22/16
23/17 24/18 25/19 26/20 27/21 28/22 29/23
30/24 31/25                              

[/HTML]

其中： 

"1/25" - 表示公历 1 号和农历 25 号。 
"立春" - 表示节气。 
"腊月" - 表示农历 12 月第一天。 

------
有关中国年历算法和程式的详细注解和二百年年历，请参考
“和荣笔记 - 中国农历二百年算法及年历”
-  http://www.herongyang.com/year_gb/