The Tibetan astrological tradition comes from both India and China (or, according to Tibetan histories, from Tibet to China). Astrological calculations and methods from India are referred to as kar-tsi and were developed out of the Kalachakra Tantra. That from China is called jung-tsi, or elemental calculation, and is related to the system of Chinese astrology. I study and practice jung-tsi, specifically I practice according to the Storehouse of Gems of All That is Desired text, which I am currently in the process of translating, under the tutelage of Khenpo Rigdzin Dorje.
It is said in the Storehouse of Gems that the specific practice of jung-tsi originates from the omniscient bodhisattva of wisdom, Manjushri, who has elucidated these calculations and methods in order to allow beings to predict and mitigate their suffering. Because we samsaric beings do not have omniscience, we cannot foresee the best course of action in many cases. Out of great compassion, the bodhisattva Manjushri has manifested as the cosmic turtle which demonstrates the methods of astrological calculation.
Jung-tsi functions along the principles of interrelations of elements. Using the five traditional “Chinese” elements of fire, earth, iron, water, and wood, we can look at the compositions of elements along aspects of a person and then compare how these elements interact with the elemental patterns of a given hour, day, month, or year. We can also use related information to calculate specific potential dangers. By following the 60 year cycle of animals, we can also see how a person’s birth year interacts with a current year. Looking at the mewas, or beads, under which a person is born can give us insight as to how this interacts with the current yearly, monthly, daily, or hourly mewa, as well as information about past lives and so on. We can also look at a person’s par-kha, or geomancy related to the I-Ching trigrams. Calculations of par-kha determine what directions are the best for people, and also gives us insight into how to best orient buildings, shrines, and so on, and how to lay out and organize houses. Looking at the stars, we can calculate the best days of the week for certain activities on an individual basis, as well as seeing how the ruling stars or lunar mansions for a given day can affect or interact with our own star’s elements, mewas, parkhas and so on.