How to Calculate the Chinese Solar Equivalent date for any western dates without using the Ten Thousand Year Calendar? Part 1 of 2
by Henry Fong
The normal way to find out the Chinese Solar or Hsia Calendar equivalent of any western date is to refer to the Ten Thousand Year Calendar Book. Another way it is to use my on-line Ten Thousand Year Calendar.
But what if you need to do a Ba Zi consultation and are caught off-line and without a 10000 year reference in your hands? What if you life depended on it? Can you save yourself?
In this article and the next, you will learn how!
Let’s start with the heavenly stem and earthly branch of the year. Assign a number from 1 to 10 to each of the heavenly stems as shown in the table below.
| Stems | Jia | Yi | Bing | Ding | Wu | Ji | Geng | Xin | Ren | Gui |
| Number | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 0 |
Next, take the last two digits of the year minus 3. For example for 1993, you take 93 – 3 = 90. Take the last digit which is 0. From the table above 0 is Gui which is the heavenly stem for the year 1993.
Let’s try another example. Let’s take 2006. The last two digit is 06 or 6. Take away 3 and you have a remainder of 3 which is Bing. For any year where the last two digit is less than 3, e.g. 2001, you take a last two digit and add 10 to it.
(Please note that the Chinese solar year starts on or around the 4th February, any date prior to this date belongs to the previous year)
To calculate the earthly branch, you need to brush up on your division. First assign the numbers 1 – 12 to the earthly branches as shown in the table below:-
| Branch | Zi | Chou | Yin | Mao | Chen | Si | Wu | Wei | Shen | You | Xu | Hai |
| Number | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
Next, take the last two digit of the year. If it is 12 or less, then read the branch of the table above. If it is 13 or higher, then divide it by 12 and take the remainder. For the year 1993, the last two digits are 93. Divide 93 by 12 and get a 7 plus remainder of 9. Add 1 to the remainder which gives 10. If you refer to the table above, 10 is the earthly branch of You.
Therefore the stem branch equivalent for 1993 is Gui You.
For years greater that 1999, you add 100 to the last two digit of the year. For example for 2006, you add 100 to the last two digits 06 to give 106. Divide 106 by 12 and you get 8 plus a remainder of 10. Add 1 to 10 gives you 11 with is the earthly branch of Xu. And true enough 2006 is the year of Xu or the Dog!
With the year out of the way, let us focus on finding the stem and branch of the month.
In the Hsia Calendar system the earthly branch of the first month is always Yin and it starts on either the 4th of 5th of February. This is followed by Mao in the second month which usually starts on either the 6th or 7th March. Next come Chen, then Si and so on until Chou. For the starting dates of the rest of the months please refer to this Chinese Solar Calendar article.
Unlike the months, the first heavenly stem of every year is not fixed. The objective is to determine the heavenly stem of the first month for any particular year. If you can do that, you can easily figure out the stem branch combination for any other months. For example if the first month is Ren Yin, the next month will be Gui Mao, followed by Jia Chen and so on which are the next stems and branches in the normal sequence of the Heavenly Stems and Earthly Branches.
Here is what you need to do to determine the stem of the first month. Write down the stems in the format below over three lines. The first and second line is the normal sequence of the stems running for left to right. The third line is also the normal sequence with the exception that it consists only of the yang stems (Jia, Bing, Ding ..) and it starts with Bing instead of Jia.
| First Line | Jia | Yi | Bing | Ding | Wu |
| Second Line | Ji | Geng | Xin | Ren | Gui |
| Third Line | Bing | Wu | Geng | Ren | Jia |
Let’s say that you want to find out the stem of the first month of the year Ding You. If you refer to the first two lines of the table above, you will see that Ding is in the fourth column. Now refer to the stem on the third line directly below Ding. What do you see? Ren, right? Therefore the stem-branch combination of the first month in Ding You year is Ren Yin.
Let’s take another example. Take the year Gui You. Gui is the last column on the second line. Immediate below Gui on the third line is Jia. Therefore the stem-branch combination of the first month in Gui You year is Jia Yin.
Suppose that the person is born on the 24th April in 1993, a Gui You year. February is the 1st month, March is the 2nd followed by April which is the third month. If February is Jia Yin, then March is Yi Mao and April which is the third month is Bing Chen. The table below should give you a clearer picture.
| Month | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Jan |
| Stem | Jia | Yi | Bing | Ding | Wu | Ji | Geng | Xin | Ren | Gui | Jia | Yi |
| Branch | Yin | Mao | Chen | Si | Wu | Wei | Shen | You | Xu | Hai | Zi | Chou |
In the next article, you will learn how to find the day pillar (stem-branch combination) as well as the stem for any of the bi-hour.
