Fundamentals

Three Cycles Nine Periods (三元九运)

Cycle theory is cultural historiography, not economic forecasting.

Definition

San Yuan divides history into nine 20-year ‘periods’ with a ruling star entering the central palace. Period 9 runs 2024–2043 with purple star 9 on centre, shifting which stars are timely for construction and renovation.

How to Check

Verify construction completion vs period transition rules your lineage uses.
Update flying-star charts when crossing 2024 if still on Period 8 assumptions.
Document whether you treat replacement buildings as new periods.

Classical Basis

《沈氏玄空学》 popularised period charts; earlier almanacs embed similar cycle thinking.

Application

·Macro timing for builds and industry trend talk.

Common Effects

·Timely stars change recommended colours, elements, and active zones.

Remedy Direction

Replot house charts for Period 9 before major layout spends.

Caveats & Debate

Exact year boundaries and ‘replacement’ rules vary; commercial hype oversells period gadgets.

Sources

《沈氏玄空学》清·沈竹礽
Period star flight.
Wikipedia: Flying Star Feng Shui
Period table.
https://en.wikipedia.org/wiki/Flying_Star_Feng_Shui
Wikipedia: Chinese calendar
Cycle cultural backdrop.
https://en.wikipedia.org/wiki/Chinese_calendar

Sources are for verification; schools may disagree.