There are 9 periods that make up a total of 180 years.

The periods 1, 2, 3 form up the upper period. Periods 4, 5, 6 make up the middle period. Periods 7, 8, 9 round up the lower period.

During any ruling period, the star that embodies wang chi is considered as the timely star. The stars that embodies sheng chi are also considered as favorable stars.

The rest are considered untimely.

However do note that even when a star is untimely, it nature might still be a good star.

Period 1 2 3 4 5 6 7 8 9
旺气 1 2 3 4 5 6 7 8 9
生气 2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
1
1
2
退气 9 1 2 3 4 5 6 7 8
死气 6
7
9
6
1
6
2
8
3
2
4
9
5
4
3
6
2
7
6
煞气 5 5
7
7
9
7
9
2
9
2
3
2
3
3
4
5
3
4
5

Legend:

  • 旺气 – Wang chi (prosperity)
  • 生气 – Sheng chi (life)
  • 退气 – Tui chi (retreat)
  • 死气 – Si chi (death)
  • 煞气 – Sha chi (killing)

With the above table, lets take for example the period of 7 which was between 1984 and 2004.

During the period of 7, the star 7 became the resident timely star. And the stars 8 and 9 became auspicious stars to tap on.

Also take note that from the above period luck table that the stars 1, 6, 8 never become sha chi in any of the 9 periods. This is because they are generally good natured stars and don’t take up that position.

Which is one reason why the number combination of 1-6-8 is such a popular combination of numbers for the Chinese.

More about the types of chi can be found here.