The Chinese Calendar 1 - What You Must Know

The historical account of the Chinese Calendric sciences are both interesting and intriguing often laden with puzzles, hypotheses and dogmas. On one hand, it needs to account for the evolutions of the GanZhi 干支 system of Heavenly Stem and Earthly Branches while on the other, the all embracing system of Yi in the forms of Hexagrams and Trigrams 卦. As commonly understood, there are 60 GanZhi as opposed to 64 Hexagrams. So technically, a complete cycle of the GanZhi 干支 system may not match the complete cycle of the system of Yi in the forms of Hexagrams and Trigrams 卦. However through the centuries, there are many attempts to consolidate both systems into a workable model and through 3 generations of Chinese Calendars was born:-

1. The first was known as TaiChu Li or the Calendar of the Great Beginning.

2. The second was known as SanTong Li or the Calendar of the Three Concordance.

3. The third was known as SiFen Li or the Calendar of the Four Remainders.

These are models based on a LuniSolar attempt or the combination of:-

1. Lunar – Calculation based on Lunation of the moon around the Earth.

2. Solar – Calculation based on Sun path in relation to Earth rotation commonly known as the Yellow Path.

Where both GanZhi and YiGua are used. In Chinese Metaphysics, both GanZhi and YiGua are equally important: -

1. SanHe – Emphasis on GanZi

2. SanYuan – Emphasis on YiGua

Are these systems measuring the same Qi? What sort of calendar does the system employ? Better, what are GanZhi and YiGua measuring to? 

If one look at the SYSTEM itself, starts from 1 WuQi, 2 Slices of YinYang, 3 Components of SanCai, 4 Seasons, 7 Luminaries, 8 Guas, 9 Stars, 10 Stems and all through 24 sub seasons and 30 pairs of NaYin to 64 Hexagrams. How would one consolidate such into a meaningful working model? 

Questions: -

1. Has any of  the basis of Yarrow Stalks Divination method has to do with calendric sciences?

2. Why would one group the 24 sub seasons into the group of three instead of two as commonly understood?

3. A trigram is made of 3 Yao (3 lines comprising the composition of solid or broken line). Why a Yang Yao (solid line) must take the value of 9 as opposed to Yin Yao (broken line) which take the value of 6 as the basis of measuring time?

If these fundamentals are not sorted out, how would one understand the working mechanism of DaGua date selections and confronting SanSha? How would one understand the use of GuaYun and GuaQi? What are these units measuring to in the first instance?