Year boundary and leap months
A Zi Wei chart first decides which day starts the year, and which side of a leap month counts. Change either one and the Life Palace, then the stars after it, can shift a cell.
Editorial review: 2026-09-22 · Reviewed by fateshow · Editorial method
Which day starts the year
January 1 is not the only day a Zi Wei year can turn. Some calculators wait for Beginning of Spring. Others use a different cut. In the days around that solar term, the two rules can place the same birth in neighboring year stems. A new stem selects a new set of natal transformations, and the star layout can start from a different cell.
Before you compare two charts, read the year boundary printed on the report. The birth date line alone does not settle it.
Which side a leap month joins
A lunar year sometimes inserts an extra month. That month can be grouped with the solar term before it, or with the one after. The grouping changes the month used to place the Life Palace. If someone was born in a leap month and the side is unnamed, the chart is not finished yet.
One birthday, two year cuts
Illustration: a birth two days before Beginning of Spring. Rule A still counts the old year. Rule B has already opened the new one. The year stems differ, so the Life Palace need not land on the same branch. Neither chart has “the wrong person.” The year was sliced on a different day. fateshow writes the year boundary and the leap-month side back onto the report. Stars compared under another cut are not the same chart. The structure also does not pick a day for surgery or a contract.
Common mistakes
- Reading the calendar year as the Zi Wei year stem.
- Assigning a leap month when nobody recorded which side it joins.
- Comparing stars across two year boundaries and asking which chart is more accurate.
Use it in fateshow
Zi Wei chart
Cast a Zi Wei chart and read the palaces, stars, and transformations it prints.
Open tool →Frequently asked questions
Does every calculator change the year at Beginning of Spring?
No. Some do, some use another cut. Use the setting printed on the chart you are holding.
Can a leap month change the month and leave the Life Palace alone?
The Life Palace is placed with the month. Move the leap month’s side and the Life Palace can change cells, taking the other names and stars with it.
The report never names the year boundary. Can I still discuss the four transformations?
Name the boundary first. Without a year stem there is no table entry for the four natal transformations.
Sources and editorial basis
- 1. iztro Zi Wei Dou Shu engine
Supports only what the current fateshow configuration actually calculates: palace placement, major-star arrangements, and the recorded year-boundary, leap-month, and transformation settings. It does not prove that any traditional school is uniquely correct.
- 2. Ziwei Doushu Quanshu (received editions)
Used to cross-check palace names, star lists, and traditional wording. A received text can record a tradition; it cannot prove scientific validity or guarantee an event.
- 3. fateshow chart rule snapshot
Each generated report stores the engine settings that produced it. Compare those settings before treating two charts as the same calculation.