There are six hexagrams in the Book of Changes, and the first one is the ninth or sixth day. So do the ninth and sixth hexagrams correspond to the last one?

It's easy to use one, two, three, four, five and up to indicate position, and nine and six to indicate virtue-nine indicates yang and six indicates yin. Since "six" is used to represent virtue, the position of the first liu de is represented by "Shang".

The six hexagrams are all yang hexagrams and pure yang hexagrams, so the word "Yongjiu" is attached, which means that "Nine" stands for yang hexagrams; Similarly, Kun's six hexagrams are all yin and pure yin, so the word ""is added to indicate that "six" stands for yin. So, why do we have to use six and nine to represent yin and yang? This is related to the divination method (see cohesion for details). The number you get every time is nothing more than "six, seven, eight and nine", and the odd number is yang, so seven and nine are yang; Even numbers are yin, so six and eight are yin. Yang goes forward, so from seven to nine, nine is the vertex and the number to be changed; Yin retrograde, from eight to six, six is the vertex, which is the number to be changed. Zhouyi is about the way of change, so six and nine are used to represent yin and yang.