**Note**: The images shown below have been cropped and resized from the originals. Only a few pages containing the information of conjunctions, intercalary months and solar terms are shown here. The digital version of the whole book can be obtained from the source link above.

皇曆未至本藩權依

大統曆法命官考訂刊行俾

中興臣子咸知

正朔用是為識

Note: The missing characters in the photo are added according to the cover photo of the Datong Calendar for the 31st Year of the Yongli Reign (1677).

The book title is *Datong Calendar for the Thirtieth Year of the Yongli Reign in the Great Ming Dynasty.*

The text roughly states that the emperor's calendar for the year had not arrived and the Prince of Yanping (governor of the Zheng state) expediently ordered officials to produce and promulgate the calendar according to the Datong system, so that the civilians under his governance could use it for their daily lives.

Note: The emperor's calendar of the Southern Ming dynasty was no longer produced after the death of the Youngli emperor in 1662. The statement may be interpreted as Zheng's expressing his loyal sentiment towards the formal emperor of the Southern Ming dynasty.

Photos:

大明永曆三十年歲次丙辰大統曆 | |||

正月小 | 甲申 | 初七日庚寅酉初一刻雨水正月中 | 廿二日乙巳亥正二刻京直二月節 |

二月大 | 癸丑 | 初九日辛酉寅初三刻春分二月中 | 廿四日丙子巳初初刻清明三月節 |

三月大 | 癸未 | 初九日辛卯未正一刻谷雨三月中 | 廿四日丙午戌初二刻立夏四月節 |

四月小 | 癸丑 | 初十日壬戌子正三刻小滿四月中 | 廿五日丁丑卯正初刻芒種五月節 |

五月大 | 壬午 | 十一日壬辰午初一刻夏至五月中 | 廿六日丁未申正二刻小暑六月節 |

六月小 | 壬子 | 十一日壬戌亥初三刻大暑六月中 | 廿七日戊寅丑正四刻立秋七月節 |

七月大 | 辛巳 | 十三日癸巳辰正初刻處暑七月中 | 廿八日戊申未初一刻白露八月節 |

八月小 | 辛亥 | 十三日癸亥酉正二刻秋分八月中 | 廿八日戊寅夜子初三刻寒露九月節 |

九月大 | 庚辰 | 十五日甲午卯初初刻霜降九月中 | 三十日己酉巳正一刻立冬十月節 |

十月小 | 庚戌 | 十五日甲子申初二刻小雪十月中 | |

十一月大 | 己卯 | 初一日己卯戌正三刻大雪十一月節 | 十七日乙未丑正初刻冬至十一月中 |

十二月小 | 己酉 | 初二日庚戌辰初刻小寒十二月節 | 十七日乙丑午正二刻大寒十二月中 |

凡三百五十四日 (divination content omitted) |

Calendar Dates for the 30th Year of the Yongli Reign (sexagenary year Bing Chen) | |||

1 S | Jia Shen | Z1: 7, Geng Yin, (17,1) | J2: 22, Yi Si, (22,2) |

2 L | Gui Chou | Z2: 9, Xin You, (3,3) | J3: 24, Bing Zi, (9,0) |

3 L | Gui Wei | Z3: 9, Xin Mao, (14,1) | J4: 24, Bing Wu, (19,2) |

4 S | Gui Chou | Z4: 10, Ren Xu, (0,3) | J5: 25, Ding Chou, (6,0) |

5 L | Ren Wu | Z5: 11, Ren Chen, (11,1) | J6: 26, Ding Wei, (16,2) |

6 S | Ren Zi | Z6: 11, Ren Xu, (21,3) | J7: 27, Wu Yin, (2,4) |

7 L | Xin Si | Z7: 13, Gui Si, (8,0) | J8: 28, Wu Shen, (13,1) |

8 S | Xin Hai | Z8: 13, Gui Hai, (18,2) | J9: 28, Wu Yin, (23,3) |

9 L | Geng Chen | Z9: 15, Jia Wu, (5,0) | J10: 30, Ji You, (10,1) |

10 S | Geng Xu | Z10: 15, Jia Zi, (15,2) | |

11 L | Ji Mao | J11: 1, Ji Mao, (20,3) | Z11: 17, Yi Wei, (2,0) |

12 S | Ji You | J12: 2, Geng Xu, (7,?) | Z12: 17, Yi Chou, (12,2) |

Number of Days: 354 (divination content omitted) |

- The first column is the Chinese month number followed by either S (short month) or L (long month). The S months had 29 days and L months had 30 days. The total number of days in the year was therefore 30N
_{L}+ 29N_{S}, where N_{L}is the number of L months and N_{S}is the number of S months. The calculated number matches the value given in the last row of the table. - The second column gives the sexagenary date cycle of the first day (conjunction day) in the Chinese month.
- The last two columns list the dates and times of the solar terms in the year.
- Solar terms are labelled using the convention on the solar term page. They are shorthand notations of the alternative Chinese names. For example, Z5 refers to the Zhongqi (major solar term) associated with month 5 (五月中), which is Summer Solstice (夏至); J6 refers to the Jieqi (minor solar term) associated with month 6 (六月節), which is Slight Heat (小暑).
- The date of a solar term is given by a number indicating the date in the Chinese month and the sexagenary date cycle. For example, "J2: 22, Yi Si" means that J2 was on the 22nd day (of month 1) and its sexagenary date cycle was Yi Si.
- Time is indicated by two numbers (x,y), where x is an integer between 0 and 23 and y is an integer between 0 and 4. If y≠4, (x,y) means that the time is between 14.4y minutes and 14.4(y+1) minutes past x o'clock. If y=4, (x,y) means that the time is between 57.6 minutes past x o'clock and (x+1) o'clock. For exampe, (20,3) refers to the time interval between 20:43:12 and 20:57:36; (2,4) refers to the time interval between 2:57:36 and 3:00:00.
- Hence, "J10: 30, Ji You, (10,1)" in the 9L row means that J10 occurred in the time interval between 10:14:24 and 10:28:48 on the 30th day of month 9 and the sexagenary date cycle was Ji You. This date corresponds to November 5th, 1676 in the Gregorian calendar.

Note: There is a number missing in the calendar for the time of J12. According to the calculation of the Datong system, the missing number is 1, making the J12 date and time as 2, Geng Xu, (7,1). The dates and times of other solar terms given in the calendar agree with the calculation of the Datong system. All the conjunction days given in the calendar also agree with the calculation of the Datong system.

Photos:

The last row in the photo is omitted in the following table.

紀年 | ||||||

永 曆 | 三十年 | 丙辰土 | 一歲龍 | 男六宮 | 女六宮 | |

廿九年 | 乙卯水 | 二歲兔 | 男七宮 | 女五宮 | 閏六月 | |

廿八年 | 甲寅水 | 三歲虎 | 男八宮 | 女四宮 | ||

廿七年 | 癸丑木 | 四歲牛 | 男九宮 | 女三宮 | ||

廿六年 | 壬子木 | 五歲鼠 | 男一宮 | 女二宮 | 閏八月 | |

廿五年 | 辛亥金 | 六歲豬 | 男二宮 | 女一宮 | ||

廿四年 | 庚戌金 | 七歲狗 | 男三宮 | 女九宮 | ||

廿三年 | 己酉土 | 八歲雞 | 男四宮 | 女八宮 | 閏十二月 | |

廿二年 | 戊申土 | 九歲猴 | 男五宮 | 女七宮 | ||

廿一年 | 丁未水 | 十歲羊 | 男六宮 | 女六宮 | 閏四月 | |

二十年 | 丙午水 | 十一歲馬 | 男七宮 | 女五宮 | ||

十九年 | 乙巳火 | 十二歲蛇 | 男八宮 | 女四宮 | ||

十八年 | 甲辰火 | 十三歲龍 | 男九宮 | 女三宮 | 閏六月 | |

十七年 | 癸卯金 | 十四歲兔 | 男一宮 | 女二宮 | ||

十六年 | 壬寅金 | 十五歲虎 | 男二宮 | 女一宮 | ||

十五年 | 辛丑土 | 十六歲牛 | 男三宮 | 女九宮 | 閏十月 | |

十四年 | 庚子土 | 十七歲鼠 | 男四宮 | 女八宮 | ||

十三年 | 己亥木 | 十八歲豬 | 男五宮 | 女七宮 | 閏正月 | |

十二年 | 戊戌木 | 十九歲狗 | 男六宮 | 女六宮 | ||

十一年 | 丁酉火 | 二十歲雞 | 男七宮 | 女五宮 | ||

十年 | 丙申火 | 廿一歲猴 | 男八宮 | 女四宮 | 閏五月 | |

九年 | 乙未金 | 廿二歲羊 | 男九宮 | 女三宮 | ||

八年 | 甲午金 | 廿三歲馬 | 男一宮 | 女二宮 | ||

七年 | 癸巳水 | 廿四歲蛇 | 男二宮 | 女一宮 | 閏八月 | |

六年 | 壬辰水 | 廿五歲龍 | 男三宮 | 女九宮 | ||

五年 | 辛卯木 | 廿六歲兔 | 男四宮 | 女八宮 | ||

四年 | 庚寅木 | 廿七歲虎 | 男五宮 | 女七宮 | 閏十二月 | |

三年 | 己丑火 | 廿八歲牛 | 男六宮 | 女六宮 | ||

二年 | 戊子火 | 廿九歲鼠 | 男七宮 | 女五宮 | 閏三月 | |

元年 | 丁亥土 | 三十歲豬 | 男八宮 | 女四宮 | ||

隆武 | 二年 | 丙戌土 | 卅一歲狗 | 男九宮 | 女三宮 |

The following table omits columns 4-6.

Reign | Year | Sexagenary Year | Leap Month |
---|---|---|---|

Yongli | 30th | Bing Chen | |

29th | Yi Mao | 6 | |

28th | Jia Yin | ||

27th | Gui Chou | ||

26th | Ren Zi | 8 | |

25th | Xin Hai | ||

24th | Geng Xu | ||

23rd | Ji You | 12 | |

22nd | Wu Shen | ||

21st | Ding Wei | 4 | |

20th | Bing Wu | ||

19th | Yi Si | ||

18th | Jia Chen | 6 | |

17th | Gui Mao | ||

16th | Ren Yin | ||

15th | Xin Chou | 10 | |

14th | Geng Zi | ||

13th | Ji Hai | 1 | |

12th | Wu Xu | ||

11th | Ding You | ||

10th | Bing Shen | 5 | |

9th | Yi Wei | ||

8th | Jia Wu | ||

7th | Gui Si | 8 | |

6th | Ren Chen | ||

5th | Xin Mao | ||

4th | Geng Yin | 12 | |

3rd | Ji Chou | ||

2nd | Wu Zi | 3 | |

1st | Ding Hai | ||

Longwu | 2nd | Bing Xu |

According to the calculation of the Datong system, the leap month in the 4th, 7th and 29th year of the Yongli reign were after the 11th, 7th and 5th month, respectively, and they are inconsistent with this table. Surprisingly, in the calendar for the 25th year of the Yongli reign, the leap month in the 7th year of the Yongli reign is recorded to be after the 6th month, inconsistent with both this table and the calculation of the Datong system.