中国农历二百年算法及年历程序分析一

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：

   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;

   }

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：

[HTML]

/**

 * 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) {