Calendar Differences Between the Qing, Southern Ming and Zheng Dynasties in 1645 – 1683

Several sources indicate that the leap month in 1648 in the Southern Ming calendar was after the 6th month, which I find to be very unlikely.

Two dfferent versions of calendar in the Southern Ming dynasty were produced in 1649. One of them was produced by the officials of the Yongli emperor, in which the New Year day was on February 11th, 1649. Another version was produced by the officials of the Prince of Lu, who named himself regent. The New Year day of the Lu calendar was on February 12th, 1649. According to the calculation of the Datong system, the New Year day was on February 11th, 1649.

According to Cán Míng Dà Tǒng Lì or Datong Calendar of the Waning Ming Dynasty by Fu Yili and Yán Píng Wáng Hù Guān Yáng Yīng Cóng Zhēng Shí Lù (or Account of the quartermaster Yang Ying's campaign with Prince Yanping), the leap month in 1650 was after the 11th month in the Southern Ming calendar. This is consistent with the calculation by the Datong system. However, the Datong calendars produced by the Zheng dynasty for 1671, 1676 and 1677 recorded the leap month to be after the 12th month. Leap month 12 was probably based on an unofficial calendar expediently produced by the Zheng officials in 1649 since the official emperor calendar had not arrived in time because of war.

Two dfferent versions of calendar were produced in 1652 in the Southern Ming dynasty: emperor Yongli's and Lu's version. The New Year day of the Yongli calendar was on February 10th, 1652. The New Year day of the Lu calendar was on February 9th, 1652. According to the calculation of the Datong system, the New Year day was on February 10th, 1652.

There are discrepancies in the leap month in the Southern Ming calendar in 1653 among various sources. Datong Calendar of the Waning Ming Dynasty records the leap month to be after the 7th month, which is consistent with the caleculation of the Datong system. Account of the quartermaster Yang Ying's campaign with Prince Yanping has the leap month after the 8th month. The chronicle Xíng Zài Yáng Qiū records the leap month to be after the 6th month. The Datong calendar produced by the Zheng dynasty for 1671 also records leap month after the 6th month. However, in the Datong calendar for 1676 and 1677, the leap month is changed to being after the 8th month. I think leap month 6 is unlikely. Both leap month 7 and 8 are possible. Here I follow Datong Calendar of the Waning Ming Dynasty and place the leap month after the 7th month.

The New Year day in 1671 in the Zheng calendar was on February 9th, 1671 according to Datong Calendar of the Waning Ming Dynasty, which also agrees with the calculation of the Datong system. However, the Datong calendar produced by the Zheng dynasty for 1671 indicates that the New Year day was on February 10th, 1671. Even though Zheng dynasty claimed that their calendars were produced expediently and should not to be taken as official, by this time the Yongli emperor had died and the Southern Ming dynasty had already ended. Zheng's calendar became the de facto official Datong calendar of the state. So I change the New Year day to February 10th, 1671 in accord with Zheng's calendar.

According to the calculation of the Datong system, in 1674 the month 6 conjunction was on July 4th and month 9 conjunction was on September 30th in the Zheng dynasty. These dates are inconsistent with the records in Datong Calendar of the Waning Ming Dynasty (July 3rd and September 29th). The dates here are based on the records in Datong Calendar of the Waning Ming Dynasty.

According to the calculation of the Datong system, in 1675 (in Zheng dynasty) a conjunction occurred on July 22nd. Datong Calendar of the Waning Ming Dynasty records a conjunction on July 23rd. The one-day difference changed the leap month in this year. July 22nd conjunction resulted in a leap month after the 5th month. July 23rd conjunction resulted in a leap month after the 6th month. Leap month 6 is also recorded in the calendars produced by the Zheng dynasty for 1676 and 1677. So I use the data in Datong Calendar of the Waning Ming Dynasty.

According to the calculation of the Datong system, in 1677 (in Zheng dynasty) the month 7 conjunction was on July 29th, which is inconsistent with July 30th recorded in Datong Calendar of the Waning Ming Dynasty and the calendar produced by the Zheng dynasty in 1677. The Zheng calendar date is used here.

According to the calculation of the Datong system, in 1678 (in Zheng dynasty) the month 6 conjunction was on July 18th, inconsistent with July 19th recorded in Datong Calendar of the Waning Ming Dynasty. July 19th is used here.

According to the calculation of the Datong system, the New Year day in 1682 in the Zheng dynasty was on February 8th, inconsistent with February 7th recorded in Datong Calendar of the Waning Ming Dynasty. February 7th is used here.