BaZi: The Zi hour controversy.

Zi hour controversy - New day starts at 11 pm or 12 pm?  

I wanted to write this since a long time ago but I have totally forgotten, until I saw Agnes comment recently. So thanks to Agnes for bringing this subject up.

I am an unfortunate person who was born around 11.45pm LAT in my hometown, so I have been researching into this subject quite extensively to figure out my correct Day Pillar. Though I am not entirely sure, I am convinced that my DM is Ji earth (which is the previous day) and not Geng metal (the next day).

There are 3 common positions BaZi practitioners take regarding Zi hour.

1. Many practitioners think the new day begins at the beginning of Zi hour, which is 11.00pm. There are only 12 Hour Pillars in a particular day, if a person is born at 11.00pm on Tuesday, he is considered to be born on Wednesday.

2. The second viewpoint is that the new day begins at 12.00 am, so Zi hour is divided in Early Zi hour and Late Zi hour. Early Zi hour belongs to the previous day and Late Zi hour will be on the next day. This method has 13 Hour Pillars in a particular day.

3. The third viewpoint is that Zi hour controversy will never be resolved, so Zi hour charts cannot be read. No divination for Zi hour - 子时不占

I take the second position, that Zi hour is divided into early Zi 子初 which belongs to the previous day and middle Zi 子半 12.00 am which is the beginning of the next day.

People who take the first position would argue that the ancient Chinese have always thought that the new day begins when Zi hour begins. That this is the traditional point of view. However, this is not entirely true. The time system had been changing since the Xia dynasty.

The book of Han (of Han dynasty) has a record that says:

夏以十三月為正，色尚黑，以平旦為朔。
Xia (dynasty) (used) the thirteen month as the true (first month), color still black, with PingDan (Yin hour) as the beginning.

殷以十二月為正，色尚白，以雞鳴為朔。
Yin (Shang dynasty) used the twelfth month as the true, color still white, with the roosters crow (Chou hour) as the beginning.

周以十一月為正，色尚赤，以夜半為朔。
Zhou (dynasty) used the eleventh as the true, color still vermilion, with the half of night (middle of Zi hour) as the beginning.

According to the history book, in Xia dynasty (2100 - 1600 BC), Yin hour was regarded as the beginning of the new day. While in Shang dynasty (1600 -1048 BC), Chou hour was regarded as the beginning of the new day and in Zhou dynasty which lasted from 1045 - 256 BC, the middle of Zi hour was regarded as the beginning of the new day. Now it is apparent that the ancient Chinese did not traditionally regard Zi hour as the beginning of the new day.

During Tang dynasty, Li ChunFeng (astronomer and mathematician), who was tasked with creating a new calendar system 麟德历 (Lin De Calender) wrote in the new book of Tang 新唐书, a phrase that says;

古历分日，起于子半

The ancient calendar divides the day, with the half of Zi as the beginning.

As far as I know, the knowledge of Life analysis began sometime in the Spring and Autumn period, around the time when Gui GuZi created the NaYin system. If back in those days they were using the middle of Zi hour as the beginning of the new day, how could we shift that to the early Zi hour?

If we look into Classical BaZi books, Master Wan YuWu, who authored SMTH (which I translate a lot in this blog), referred this subject to 革象新书 (The new book of Ge Xiang), a book from Yuan Dynasty that says:

若子时，则上半时在夜半前，属昨日，下半时在夜半后，属今日.
If it is Zi hour, the half of the hour before the middle of the night belongs to the previous day, the later half after the middle of the night, belongs to today.

And therefore, I rest my case.