Buddha spoke of karma, as recorded in his sutras, while his disciples and later generations elaborated his teachings on karma in their abhidharma compilations.

The Sautrantika explanation of karma arose as a critique of the Sarvastivada abhidharma presentation that was later codified as the Vaibhashika view.

The Vaibhashika explanation of karma derives from the abhidharma texts of Vasubandhu and their Indian commentaries.

Tibetan astrology has materials that are similar to or derived from systems from India and China but are modified and used in very different ways to constitute the unique Tibetan system. Much of the materials for the study of these topics derive from the “Kalachakra Tantra.”

Ten heavenly bodies are treated in the Kalachakra system, all of which are called “planets.” A common feature with the ancient Greek and Hindu systems is the naming of the days of the week after the planets.

The Chinese-derived, or “black calculations,” also called “element calculations,” adds a few more features to the Tibetan calendar, such as correlations with animal and element cycles.

Magic-squares consist of a grid of three by three with numbers in each row and column adding to 15. Each number is correlated with a color and one of the five Chinese elements. In the Tibetan astro system, each year and each date has a magic-square number.

An overview of the history of astrology in China and India, how they came to and developed in Tibet and, from there, to Mongolia and Central Asia.

A comparison of the Kalachakra, Hindu and Chinese New Years as well as the Chinese and Kalachakra systems of seasons. Although the Tibetan element-animal assignment system may be reminiscent of the Chinese, yet on closer examination there are significant differences.

The daily positions of the planets are calculated according to complex arithmetic formulas. The Tibetan mathematical model of the motion of the planets differs greatly from the Indian and Chinese ones.