## Stems & Branches

The **10 heavenly stems** in combination with the **12 earthly branches** form a group of 60 unique time combinations called the **sexagenary cycle**. The first stem S01 moves in a circular way to the last stem S10. After that the cycle starts allover again at S01. This is the same with the branches: The first branch B01 moves in a circular way to the last branch B12. After that the cycle starts allover again at B01.

There are 4 types of stem & branch combinations each connected to a specific timeframe: Yearly stem & branch, monthly stem & branch, daily stem & branch and hourly stem & branch. The latter is actual a zodiacal 'double hour'.

To use these stem and branches some calculations have to be made:

- Before starting it is absolutely necessary to determine the correct time. To make a reliable calculation of the open acupuncture points at a certain moment your Local Time has to be converted to the Local Solar Time. This includes corrections on timezone, daylight saving time and geographical longitude.
- Calculate stem and branch of the YEAR.
- Calculate stem and branch of the MONTH.
- Calculate stem and branch of the DAY.
- Calculate stem and branch of the HOUR.
- Use the different stems and branches in different methods to lookup open acupuncture points according to Na Zi Fa, Na Jia Fa, Ling Gui Ba Fa and

Fei Teng Ba Fa.