Born after 11 pm: early and late Zi hour in BaZi

The Zi hour runs from 11 pm to 1 am. For births between 11 pm and midnight, schools disagree on whether the Day Pillar belongs to that day or the next, and a different Day Pillar means a different Day Master. This guide compares both methods on the same birth time and explains how to choose.

Where the problem comes from

The twelve double-hours begin with Zi, from 11 pm to 1 am, which straddles midnight. Modern calendars change the date at midnight, while traditional timekeeping usually started the new day as soon as the Zi hour began. That leaves the hour from 11 pm to midnight in question: does it belong to today or tomorrow?

The Year and Month Pillars follow the solar terms and are unaffected, and the hour is Zi either way. What changes is the Day Pillar, and its stem is the Day Master, the character that represents you. Someone born in this hour can therefore end up with two entirely different Day Masters.

The two main methods

MethodBorn 11 pm to midnightBorn midnight to 1 am
Change the day at 11 pmNext day's Day Pillar and next day's Zi hourThat day's Day Pillar (already past midnight) and its Zi hour
Separate early and late Zi hourSame day's Day Pillar, with the next day's Zi hourSame as above

The two methods only disagree between 11 pm and midnight; after midnight they are identical. The second method calls midnight to 1 am the early Zi hour and 11 pm to midnight the late or night Zi hour. A minority approach also derives the late Zi hour's stem from the same day; it is rarely used.

One birth time, two charts

Take a birth at 11:30 pm on 1 January 2000, already converted to true solar time. Both methods agree on the Ji-Mao Year Pillar and the Bing-Zi Month Pillar. The difference is the Day Pillar:

Year Pillar己卯
Month Pillar丙子
Day Pillar己未Day Master Ji Earth
Hour Pillar甲子
Method one: day changes at 11 pm
Year Pillar己卯
Month Pillar丙子
Day Pillar戊午Day Master Wu Earth
Hour Pillar甲子
Method two: separate early and late Zi hour

1 January 2000 is a Wu-Wu day and 2 January a Ji-Wei day. Under method one the Day Master is Ji Earth (yin Earth); under method two it is Wu Earth (yang Earth). The Day Branch also changes from Wu Fire to Wei Earth. Both Day Masters are Earth, yet every Ten God has to be recalculated, and the strength assessment and overall reading change with them.

Why the Hour Pillar is Jia-Zi in both: by the traditional rule for hour stems, the Zi hour of a Ji day is Jia-Zi. Method one is already on the Ji day; method two keeps the Wu day pillar but takes the hour from the following Ji day, which is also Jia-Zi.

Which method to use

Both methods have classical support and there is still no consensus. bazitao uses the 11 pm day change by default, which is currently the more common practice, and states this in the chart's time settings.

  • First confirm the birth really was after 11 pm, using true solar time. A birth at 11:40 pm by the clock in Chengdu may convert to before 11 pm, in which case the question does not arise.
  • If the birth really was between 11 pm and midnight, calculate both charts and compare which Day Master sounds more like you.
  • When another site disagrees, check the Day Pillar first. If it differs, the readings that follow cannot be compared directly.

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All 34 entries
Introduction and Chart SetupTrue solar time: why BaZi does not use clock time directly

BaZi divides the day by the sun's actual position at your birthplace, while China Standard Time is one clock for the whole country. Xinjiang, Tibet and Sichuan differ from it by one to two hours, so anyone born near an hour boundary may have a different Hour Pillar. This guide explains how true solar time is calculated, with a city offset table and a worked example.

Introduction and Chart SetupWhy do different BaZi calculators give different results?

When websites or AI tools give different BaZi results, the discrepancy often begins before interpretation: how the birth time is converted and how the pillars are calculated. Compare the eight characters before comparing conclusions.

Introduction and Chart SetupCan you calculate BaZi without knowing your birth hour?

Without the hour, the year, month and day still provide three pillars and six characters. They offer a Day Master and a partial elemental picture. Leave Hour Pillar matters uncertain rather than inventing a time.

Introduction and Chart SetupBaZi basics: Heavenly Stems, Earthly Branches and the Four Pillars

BaZi records a birth time using Heavenly Stems and Earthly Branches: two characters each for the year, month, day and hour. This introduction explains these eight characters, the sixty-pair cycle and the Four Pillars.

Introduction and Chart SetupDaylight saving time and chart casting: that extra hour on the clock

Mainland China observed daylight saving time during designated summer periods from 1986 to 1991. For births recorded while it was in effect, subtract the extra hour before the subsequent chart-time conversion; otherwise the Hour Pillar may differ.

Day Master and Strength/WeaknessThe ten Day Masters: traditional images of Jia, Yi, Bing and more

The Day Master is the Heavenly Stem representing you in a BaZi chart. Each of the ten stems has a traditional image, such as a tree for Jia, the sun for Bing or rain and dew for Gui. These images offer an accessible introduction.

Born After 11 pm? Early and Late Zi Hour in BaZi · bazitao