Decade luck (daeun): the 10-year seasons of your saju

The slow clock in your chart

Your four pillars are the chart you’re born with. Daeun (대운) adds a second layer: a sequence of ten-year periods, each carrying its own stem and branch — its own elements — that press on the balance of your natal chart for about a decade at a time.

So the same person reads differently at 25 and at 45, not because the birth chart changed, but because the decade sitting on top of it did. Daeun is the seasonal weather of a life.

Which decade you’re in

Daeun doesn’t start at birth. It begins at an age set by your chart — derived from your month pillar and a forward or reverse direction fixed by your birth year’s polarity and your sex. From there, each ten-year pillar follows in sequence.

That starting age (your daeunsu) is why two people the same age can be in very different luck seasons: one may have entered a new decade at 3, another at 8, so their cycles never line up.

Why a “good” decade is really a balancing one

A favorable daeun is simply one whose elements supply what your natal chart lacks — a tailwind season. An unfavorable one piles more onto what your chart already has in excess, and asks for pacing. Neither is fortune or doom; both are terrain you can plan around once you can see them.

This is the honest use of decade luck: not “these ten years are lucky,” but “this decade leans toward X, so lean with it.”

Decade sets the season, the year brings the weather

Daeun is the slow layer; the annual cycle (세운) moves on top of it, year by year. A reading worth its salt places the two together — which decade you’re in, and how the current year meets it — rather than treating either alone.

Getting the cycles right

Your daeun start age and direction depend on correct pillars, which depend on solar-term boundaries and your birthplace’s local time. Get the month pillar wrong and the entire decade timeline shifts — another reason the calculation has to come before the interpretation.