The sky is dry and people can see it at a glance. The earthly branch is unknown.
The sky is as dry as a tree, and the ground branches as roots. Trees without roots can only be dead trees. In other words, everything without roots is lifeless and full of vitality.
The eight characters are good or bad, and there is a judgment in the sky, and so is the ground branch. There are good days and bad days. Earthly branches are also useful and taboo, that is, auspicious and fierce.
So it is very important to judge the earthly branch.
Where there is a blessing in the land, there must be a good thing. If there is evil on the earth, there must be evil.
As for all the changes, it depends on the specific situation of birth and grams. For example, it is good to have an auspicious thing in the underground branch, but there are restrictions on it, so a good thing is a bad thing. On the contrary, if it is fierce, there are other constraints, which is a good thing.
I hope you can understand.