Unknown Birth Time in BaZi: First, Find Out Whether Your Chart Even Needs It
Plenty of people don't know what time they were born. The certificate is lost, the family can't remember, or all anyone recalls is "sometime in the evening." The good news: three of the four pillars need no hour at all. The bad news: strength and the favorable elements often turn on exactly that missing pillar. Rather than guess, cast all twelve hours and see which conclusions come out the same whichever hour it was.
All twelve hours at once: does your chart need the hour?
Enter your Gregorian birthday. The tool casts a chart for each of the twelve two-hour periods from Early Zi to Hai (plus the Late Zi hour) and marks which conclusions about strength, favorable element and structure hold whatever the hour, and which change. Everything is calculated in your browser; nothing is uploaded.
Uses your Gregorian birthday, with the day changing at 11 p.m. If you know the rough time of day (say, "morning"), just read those rows.
Without the hour: what is certain and what can change
| What | Without the hour | |
|---|---|---|
| Certain | Year, month and day pillars; the Day Master; the month branch | The same in all twelve hours (except the Late Zi hour and solar term days) |
| Mostly certain | Structure; the sequence of luck pillars | The structure is the same across all twelve hours for 51.1% of birthdays, and the rest still agree in 11.1 hours on average. The luck pillar sequence does not depend on the hour (except on term days), and the starting age differs by only 0.57 years on average |
| Often changes | Strong or weak; favorable element and favorable elements | Strength is the same in all twelve hours for only 21.2% of birthdays; the favorable element, for 31.6% |
| Unknown | The hour pillar; the children and later-life palace; the hour pillar's Ten Gods | Needs the hour |
How we counted: we took every fourth day from 1960 to 2005, 4,201 birthdays in all, cast a chart for each of the twelve hours from Early Zi to Hai, and used our engine to compare strength, favorable element and structure across the twelve.
In other words, the Day Master, the month branch and the structure usually hold without the hour and are safe to read. Strength and the favorable element swing with the hour for most people: on average 9.2 of the twelve hours agree on strength, and the other two or three tip the other way. The most honest reading goes with what most hours say and keeps the minority in mind.
A fairly stable chart: the hour only touches the edges
Born August 1, 1992 (Gregorian), hour unknown
- Three pillars: Ren-Shen, Ding-Wei, Ji-You. The Day Master is Ji Earth, born in the Wei month, and the month branch gives an Indirect Resource structure.
- The twelve hours: every one of them gives the Indirect Resource structure; 12 of the twelve read the Day Master as balanced; in 10 the favorable element is Fire.
- How to read it: even without the hour, "balanced, favorable element leaning to Fire, Indirect Resource structure" is safe to work with. Only a few hours (in red in the tool) push the answer the other way.
Two exceptions: the Late Zi hour and solar term days
- The Late Zi hour: if you were born after 11 p.m., we change the day at 23:00, so the day pillar moves to the next day and the Day Master is different altogether. If family say it was "very late, nearly midnight," read both days' charts. See Early and Late Zi hour.
- Solar term days: on about 3.2% of birthdays a jie solar term changes during the day, so the month pillar changes partway through, and the structure with it. On the day of the Start of Spring, even the year pillar changes. See solar term boundaries.
Three common misunderstandings
Without the birth hour you can't read a BaZi chart.
Three pillars settle the Day Master, the month branch, the structure and the order of the luck pillars, which is enough to see the broad lines of character and the rhythm of a life. What you hold back on is strength, the favorable element and anything tied to the hour pillar.
A three-pillar chart gives me my real result.
When cast with three pillars, we plug in noon and give the hour pillar no weight in strength. In our engine simulation it agrees with the majority of the twelve hours 89.6% of the time for strength, a decent starting point; but if your real hour is one of the two or three that disagree, the answer is different.
Just pick any hour and cast the chart.
Pick the wrong hour and strength and the favorable element can come out exactly reversed. Rather than choosing one, cast all twelve and see where the majority lies and where the split is.
Read next
A straight word: without the hour pillar, a quarter of the chart is missing
A BaZi chart has four pillars, and each missing one is a missing piece of the puzzle. Three pillars still show a great deal, but if your strength sits right on the line, you were born on a solar term day, or the hour decides your structure, the conclusions will wobble without it. We would rather mark what can change with the hour than pretend to know it for you. Everything on this site is for reference and entertainment.
Know the rough time of day? That narrows it down
The in-depth reading can run on three pillars if you choose "hour unknown." If you can find out the rough time of day, choosing that hour gives a fuller reading.
Unknown birth hour FAQ
Can I get a BaZi reading without my birth time?
Yes. The year, month and day pillars need no hour, so the Day Master, month branch, structure and luck pillar sequence are all there. Strength, the favorable element and anything tied to the hour pillar, such as children and later life, can change with the hour.
Without the hour, is my strong or weak reading reliable?
Not necessarily. In our engine simulation only 21.2% of birthdays have the same strength in all twelve hours. Cast all twelve hours and go with the majority.
Which hour should I choose if I don't know my birth time?
Don't choose at random. Either select "hour unknown" and cast three pillars, or use the tool on this page to cast all twelve hours and see which conclusions the hour does not affect.
How can I find out my birth time?
Start with the birth certificate, any child health record, and family papers; then ask relatives who were there. Even a rough time of day helps. The page on recovering your birth hour covers the steps.