Pre-Chart Verification: Year Pillar vs Zodiac Boundaries

Before a chart is calculated, the data behind it should be checked. Most errors in bazi work do not come from the calculation engine but from the input layer: which calendar was used, what the clock time meant, whether the birth information was complete, and whether the resulting pillars were actually reviewed. This entry describes the checks applied before 排盘.

排盘之前要核对的四项

Four items are checked before a chart is cast: the calendar basis, the time zone and clock-time convention, the sex and data-entry fields, and the output of the charting tool itself. These checks are not interpretive; they concern whether the recorded birth moment is being converted into the correct four pillars.

The first distinction is between common calendar boundaries and the boundaries used in bazi. The Gregorian New Year and the lunar New Year both matter in daily life, but neither is the boundary for the year pillar. The year pillar changes at 立春, the beginning of the solar term. The zodiac sign, by contrast, changes at the lunar New Year. These two lines usually differ by about half a month. A birth in that interval can therefore belong to one zodiac year under the popular convention and to a different year pillar under the technical convention.

The second distinction concerns the month pillar. It changes only on the twelve “jie” nodes: 立春，惊蛰，清明，立夏，芒种，小暑，立秋，白露，寒露，立冬，大雪, and 小寒. The intervening “qi” nodes, such as 雨水，春分, and 谷雨, mark the middle of a solar month but do not change the month pillar. A calendar date that falls near one of these middle nodes is not, for this purpose, a month boundary.

The third item is the exact moment of a node. A solar-term crossing is an astronomical instant, not a whole calendar day. The same term can fall at times that differ by more than ten hours across years. A person born on the day of a node therefore needs the birth time checked to the minute. A date alone is not sufficient when the birth occurred on a boundary day.

The fourth item is the output check. Even when the input is correct, the chart should be compared against an independent reference for the day pillar and for the hour branch. The point is not to trust the software but to see whether the software reproduced the intended conversion.

历法：公历、农历与节气月

The calendar layer is the first place where a chart can go wrong. The year pillar uses the 立春 boundary. It does not recognise 1 January, and it does not recognise the first day of the first lunar month. A birth in late January or early February may be before 立春 in one year and after it in another, so the year pillar must be checked against the node time rather than against the printed calendar.

The month pillar uses the twelve jie nodes listed above. Only these nodes change the month. The qi nodes do not. This means that a person born a few minutes before 惊蛰 is still in the previous month pillar, while a person born a few minutes after it has entered the next month pillar. The same applies at 清明，立夏, and the other jie nodes. A charting tool that changes the month at the qi nodes is using a calendar convention different from the one described here.

The engine used by this site stores solar-term data to the minute. The covered range is from 1899 to 2101. Years outside that range are rejected with an error rather than filled with estimated values. This is a deliberate boundary: the tool does not silently extrapolate. If a date is outside the supported range, the user must supply an external calculation rather than relying on the engine.

时区与钟面时间的口径

The hour branch depends on the clock-time convention. The 子 hour is the only one of the twelve double-hours that crosses midnight. It runs from 23:00 to 01:00 the next day. A birth between 23:00 and 23:59 is treated here as late 子. Under this convention, the day pillar advances to the next day, while the hour pillar is still calculated from the actual clock time of birth. The classical sources contain both views. There is no universally accepted correct answer; there is only a choice of convention, and this site follows the late-子 rule for the day pillar.

Two other time corrections are sometimes confused with the 子 question. The equation of time varies over the year from roughly minus fourteen minutes to plus sixteen minutes. It depends only on the date, not on the place of birth. The longitude correction, by contrast, depends entirely on the birth longitude. The four pillars produced by this site are calculated from the clock-face time as entered. Any adjustment for the equation of time or for longitude is the user’s responsibility before the time is entered. The tool does not silently apply a local mean time correction.

A proper calendar review is not the phrase “already converted.” It is a record. It should show the original date, the original calendar, the basis of conversion, the candidate Gregorian date, and which pillars are affected. A note that says “converted” without those fields does not allow the conversion to be checked.

性别与资料填写的影响

Sex does not change the four pillars themselves. It changes the direction of the ten gods in later analysis and may affect how certain software displays the luck cycles. In a charting form, sex is therefore not a decorative field. If it is entered incorrectly, the pillars may still look correct while the derived labels and directions are wrong.

The same applies to other biographical fields. The birth date, birth time, and place are the core inputs. If the place is missing, the tool may default to a time zone that is not the one intended. If the date is entered in the wrong calendar, the entire conversion shifts. These fields should be checked one by one before the chart is accepted.

When the time field contains words such as “about,” “roughly,” “family said,” “registered later,” or “daylight saving uncertain,” the entry should be marked in red. Until that mark is removed, the language of the reading should not become more confident. A birth time described as approximate cannot support minute-level claims about a term crossing or an hour boundary. The red mark is a reminder that the data quality is lower than the appearance of the chart suggests.

排盘工具输出的核验方式

The output of a charting tool should be checked against the input, not accepted as proof of itself. Five self-checks are used. The first is whether the year pillar follows the 立春 boundary. The second is whether the month pillar follows the jie nodes. The third is whether the day pillar matches a perpetual calendar for the chosen date. The fourth is whether the hour branch matches the chosen time convention, including the late-子 rule where relevant. The fifth is whether the hidden stems and ten gods match the four pillars.

These five checks do not involve differences between schools. They are mechanical. A chart that fails one of them has an input or conversion error, not a stylistic disagreement. When all five checks pass, the chart is still only as good as the underlying birth data, but the conversion from that data to the pillars has been verified.

The five checks are applied in order. If the year check fails, the month and day checks may also fail even though the data entry was otherwise careful. If the day check fails, the hour check should be repeated after the date is corrected. The hidden-stem and ten-god check is the last because it depends on the four pillars already being right. A mismatch there usually means that a pillar was changed manually or that the software used a different table.

The purpose of 排盘前的核对 is not to add interpretive depth. It is to keep the chart from being built on a date that was never the birth moment, a clock time that was never defined, or a conversion that was never recorded. The checks listed here are the minimum set applied before any reading proceeds.