BaZi Concepts
What Is the 10-Year Cycle (Da Yun) in BaZi?
Also called: Da Yun, Dayun
Plain Explanation
A 10-Year Cycle is a period in BaZi represented by a Stem–Branch pair, with a new period beginning every ten years.
Example
Suppose a chart shows that you are in a Ding (丁)–Mao (卯) 10-Year Cycle. Ding and Mao are the cycle’s Stem and Branch for that decade. The birth chart retains its original Four Pillars. To examine a particular year within that period, compare it with that year’s Annual Cycle.
What It Is Used For
10-Year Cycles are used to examine changes in how the same birth chart’s components work together across different decades. For example, when entering a Ding (丁)–Mao (卯) cycle, Ding and Mao are included in the analysis to see how they support, drain, or restrain the chart’s existing elements and Ten-God relationships.
Common Misunderstandings
Da Yun does not mean good luck
The term identifies a time scale. Whether a particular cycle is favorable depends on how it interacts with the birth chart.
A ten-year duration does not mean the first cycle starts at age ten
Ten years is the length of each cycle. When the first cycle begins depends on its start time, called Qi Yun.
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Updated 2026-10-16 · Editorial Policy