How does Xingge cast a chart?

Enter the same birthday on two chart sites and you will sometimes get two different charts. Usually nobody has made a mistake; each site simply follows its own conventions. This page lays out all of Xingge's: which book we follow, where we depart from it, how we handle your birth time, and what we cannot do yet.

Our source: the Quan Shu

Zi Wei Dou Shu has many schools. Xingge takes as its baseline the most widely circulated classic, one whose original text anyone can read: the Quan Shu, or Zi Wei Dou Shu Quan Shu (The Complete Book of Zi Wei Dou Shu).

• Placing the Life Palace, the Body Palace, the main stars and the auspicious and challenging stars: by the placement verses in volume two.
• Brightness (Miao, Wang, Li, Xian and the rest): by the brightness table in volume two. Every star that has a brightness has been checked in every branch. The table is written into automated tests, so if a code change breaks even one square, it cannot ship.
• The four transformations: by the verse in volume two, also locked in by automated tests. Schools disagree most about the Wu, Geng and Ren years. Xingge's version: in Wu years You Bi takes Hua Ke, in Geng years Tai Yin takes Hua Ke, and in Ren years Tian Fu takes Hua Ke.

The Quan Shu is not always consistent with itself. The star descriptions in volume two, for example, give a different brightness from the brightness table in the same volume in more than twenty places. When that happens, Xingge always follows the table.

Where we depart from the Quan Shu

In a few places Xingge follows the conventions most modern charts use. The main ones:

• The first Decade Luck starts in the Life Palace. The original text starts it in the palace next door; most modern charts, and Xingge, start in the Life Palace.
• The Twelve Life Stages run by yin-yang and gender. The original text has them run forward for men and backward for women; Xingge runs them in the same direction as the Decade Luck.
• A leap month splits at the fifteenth day. Days one to fifteen count as the current month, sixteen onward as the next. The original text counts the whole leap month as the next month.
• Late Zi hour counts as the next day. If you were born after 11 p.m., the date rolls over to the following day.
• Minor stars added in later centuries. A few stars, such as Xian Chi, Tian Cai, Tian Shou and Tian Chu, are not in the original placement verses. Xingge places them the way most charts do.

When you compare with another app, the differences you are most likely to see are in the Decade Luck and the Twelve Life Stages, and they usually come from the first two items above.

On this chart the Decade Luck moves clockwise, one palace every ten years.

Ages 24–33: the Decade Luck sits in the Fortune Palace, and this palace sets the theme for those ten years.

This is a sample chart. Enter your birth details and the diagram switches to your own chart. Draw a chart ›

How your birth time is corrected

Zi Wei Dou Shu works in double-hours, two hours each. Xingge turns the time you enter into a double-hour in this order:

1. You enter the clock time at your birth. The time on a birth certificate, or the one your family remembers, is the time the clock on the wall showed then.
2. Clock changes are taken out. Taiwan used Japan time, one hour ahead, from October 1937 to September 1945, and observed daylight saving time, also one hour ahead, in the summers of 1946 to 1961, 1974 to 1975, and 1979. If your birth falls in one of these periods, Xingge sets the time back an hour automatically and notes it on the chart.
3. The time becomes a double-hour. For example, 11 p.m. to 1 a.m. is the Zi hour, and 1 a.m. to 3 a.m. is the Chou hour.

If your birth time falls within fifteen minutes of the line between two double-hours, Xingge will tell you the other one is possible too. That is worth asking your family about, or you can read both charts.

If you only know the double-hour and not the exact time, you can pick the double-hour directly, and none of the corrections above apply.

Born outside Taiwan

The mainstream practice in Zi Wei Dou Shu is to use the local clock time where you were born, without converting it to Taiwan or Beijing time. Born at 10 a.m. in New York means 10 a.m.

When you enter an exact time, you can choose the country and city you were born in (Taiwan is the default). Xingge checks whether daylight saving time was in force there on that day of that year, and if it was, sets the clock back and notes it on the chart. Mainland China's daylight saving from 1986 to 1991, Hong Kong's, and wartime time in the United States are all included. The data comes from the IANA time zone database, the international standard.

On the day clocks spring forward, one hour never appears on the clock; on the day they fall back, one hour happens twice. If your birth time lands in either of those hours, Xingge casts the more likely chart and tells you about the other possibility.

True solar time: optional, off by default

Some schools use "true solar time": adjusting the clock time by the longitude of your birthplace to match where the sun actually was. Taipei sits at 121.5° east, one and a half degrees from the 120° meridian that standard time is based on, so it runs about six minutes ahead; Kinmen, at 118.3° east, runs about seven minutes behind. Add the equation of time, which shifts through the year, and the difference can reach a dozen minutes or more either way.

The reasoning holds up, but practitioners disagree, and the classics don't do it, so by default Xingge casts the chart by clock time, with clock changes taken out. To use true solar time, turn on "Use true solar time" when you enter an exact time, and choose your county, city or birth city. If you choose "anywhere in Taiwan" or "other", there is no longitude to work with, so Xingge uses clock time and notes it on the chart.

What we cannot do yet

• The birthplace list is limited. It covers every county and city in Taiwan and about fifty common cities elsewhere. If your birthplace isn't listed, choose "other": the chart uses the local time you enter, without daylight saving correction. If daylight saving time was in force where you were born, subtract an hour yourself first.

Why this page exists

Casting the chart is only the starting point, but if the starting point is wrong, no amount of careful reading afterward will help. With our conventions written down, you will know where any difference comes from when you compare a Xingge chart with another site's, and every reading you see on Xingge can be traced back to the chart it stands on.

To see your own chart, you can draw it for free.

Common questions

Why is my Xingge chart different from another site's?

There are three usual reasons: which palace the first Decade Luck starts from, which direction the Twelve Life Stages run, and which day counts for a birth after 11 p.m. Different sites follow different conventions, so the charts come out different. Xingge follows the Quan Shu, and every place we depart from it is listed on this page.

Does Xingge account for daylight saving time?

Yes. Taiwan used Japan time from 1937 to 1945, and observed daylight saving time in the summers of 1946 to 1961, 1974 to 1975, and 1979. If you were born in one of those periods, Xingge sets the time back an hour automatically and notes it on the chart.

Does Xingge use true solar time?

Not by default, but you can turn it on. Practitioners disagree about true solar time and the classics don't use it, so by default Xingge casts by clock time, with clock changes taken out. To use it, turn on "Use true solar time" when you enter an exact time, and choose your county, city or birth city.

Can I use Xingge if I was born outside Taiwan?

Yes. Zi Wei Dou Shu uses the local time where you were born, with no conversion to Taiwan time: if you were born at 10 a.m. in New York, enter 10 a.m. and choose New York as your birthplace. Xingge corrects for the daylight saving time in force there at the time.