Dayun — The Ten-Year Chapters of Life

Dayun divides life into ten-year chapters. Its direction and starting age both come from your birth.

What Dayun Is

Dayun (literally "great cycle") divides a life into ten-year chapters. From your starting age, each ten-year segment is governed by one stem-branch combination — a single "step" of dayun.

Each dayun pillar interacts with your natal four pillars — through generation, control, support, restraint, union, clash, punishment, harm — and these interactions set the tone of that decade.

Direction — Forward or Reverse

Dayun begins from the month pillar and moves in a direction set by year-stem polarity × gender:

• Yang-year (甲丙戊庚壬) male: forward (next pillar in the 60-jiazi sequence)
• Yang-year female: reverse
• Yin-year (乙丁己辛癸) male: reverse
• Yin-year female: forward

Mnemonic: "Yang-male and Yin-female go forward; Yin-male and Yang-female go reverse."

Starting Age — Different for Everyone

How "starting age" is computed:

• For forward dayun: count from your birth moment forward to the next Jie solar term
• For reverse dayun: count backward to the previous Jie solar term
• Convert: every 3 days = 1 year

Example: a man born 3 September 1986 at 2pm — year stem 丙 is Yang, male → forward. The next Jie (白露 / Bailu) falls on 8 September — about 5 days later — which converts to ~1 year 9 months. So this person starts dayun at age 2.

The First Dayun Step

The first dayun is NOT the month pillar itself — it's the next (forward) or previous (reverse) pillar:

If the above man's month pillar is 丙申, going forward → first dayun = 丁酉 (the next jiazi after 丙申). This runs from age 2 to 12.

Then: second dayun 戊戌 (12–22), third 己亥 (22–32), and so on.

What Makes a Dayun "Good"

Dayun quality is not a single label — it depends on whether:

• The dayun element supplies your favourable element (yongshen)?
• It restrains your unfavourable element (jishen)?
• It generates clashes, unions, or punishments with your natal chart?

A chart with fire-blaze needing water (climate yongshen) — if dayun is 壬子 (water), the yongshen arrives. If dayun is 丙午 (more fire), the heat compounds.

Same person, different dayun, completely different decade. The art of reading often turns on the moment of dayun transition.

Next step

Read about annual luck (流年) — each year's standalone tone.