XiaodaoLife · Good fortune

Can You Look Up a BaZi Chart Directly by the Four Pillars or Without an Exact Birth Time?

Last updated: October 22, 2026

If you already have the eight characters of a chart (the Year, Month, Day, and Hour stem–branch pairs from a written reading or historical text) and want to find the matching calendar dates or view the chart structure, switch to the "Pillars" tab in Xiaodao's BaZi Calculator. The tool filters out invalid stem–branch combinations and searches 1801–2099 for matching time windows.

Keep two product boundaries in mind: first, a profile created via four-pillar reverse lookup is labeled "By Four Pillars"—it is not a complete profile with a verified birth time, has only the four pillars, and can only view the natal chart parts it displays (it cannot be used for Bazi Reports, Bazi Q&A, Daily Fortune, With-Bazi mode, or One-tap MBTI);1 second, when entering a birth by Gregorian or Lunar date, birth hour and minute are required, and Xiaodao does not substitute a fake noon time when the birth hour is unknown (guests can preview the four natal pillars and chart header; Luck Pillars, annual and monthly cycles, and the Timeline are available after registering and saving a complete profile).

How to Reverse-Lookup Dates from Known Four Pillars (1801–2099)

In the traditional sexagenary (Jia-Zi) calendar, Heavenly Stems and Earthly Branches only pair with matching polarity (Yang with Yang, Yin with Yin), the Month Stem is constrained by the Year Stem, and the Hour Stem is constrained by the Day Stem.2 Because the 60-year cycle and 60-day cycle repeat at different intervals, a given four-pillar combination only occurs during specific two-hour windows across a century.

To look up a chart by its pillars on Xiaodao:

  1. Select the "Pillars" Tab: Open Cast a Bazi chart and switch the calendar selector from "Gregorian" or "Lunar" to "Pillars".
  2. Select the Stems and Branches for Year, Month, Day, and Hour: As you pick each stem and branch, the selector automatically filters out impossible combinations so you cannot accidentally assemble an invalid chart (use "Clear" to reset your selections at any time).
  3. Choose a Matching Time Window: Xiaodao searches 1801–2099 and lists the matching date and time windows under "Matching Bazi" (if the Hour Branch is Zi, windows are labeled "Early Zi" or "Late Zi"; see BaZi 12 Two-Hour Branches Table). Select the matching window and click "Confirm" to view the natal chart.

(Note: If the search returns no matches, it means that combination does not occur within the 1801–2099 lookup window, not necessarily that the combination never existed in earlier historical centuries.)

Comparison: "Gregorian" vs. "Lunar" vs. "Pillars" Profiles on Xiaodao

A profile created via four-pillar reverse lookup is labeled "By Four Pillars"—it is not a complete profile with a verified birth time and has only the four pillars. Here is how Xiaodao's three profile input modes compare (guests can preview the four natal pillars and chart header; registering and saving a complete profile unlocks Luck Pillars, annual and monthly cycles, and the Timeline):1

Feature"Gregorian" Input"Lunar" Input"Pillars" Reverse Lookup
Supported Year Range1900 to present year1801–2099 (includes "This is a leap month" checkbox)1801–2099 reverse date-window lookup
Required InputsGregorian date, local clock hour & minute, sex, birthplaceLunar date (and leap-month status), local clock hour & minute, sex, birthplaceYear, Month, Day, and Hour stems/branches, sex, and selection of a matching window
True Solar Time & DSTAutomatically adjusted by birthplace and dateAutomatically adjusted by birthplace and dateNot applicable (no birthplace or exact clock minute)
Saved Profile Status Badge"Complete""Complete""By Four Pillars"
Free Chart ViewGuests preview 4 natal pillars & header; registering and saving a profile unlocks Luck Pillars, annual/monthly cycles & TimelineGuests preview 4 natal pillars & header; registering and saving a profile unlocks Luck Pillars, annual/monthly cycles & TimelineCan only view the natal chart parts it displays
One-tap MBTI (uses Dao Points)SupportedSupportedNot supported
11-Chapter Bazi Report & Bazi Q&A (Xuan-tier+, uses Dao Points)SupportedSupportedNot supported
Daily Fortune & With-Bazi Everyday Delights / Meeting (uses Dao Points)Supported (once profile has a Bazi Report)Supported (once profile has a Bazi Report)Not supported (Time-only Qimen readings remain available without a profile)

What If You Know Your Birth Date, But Not Your Birth Time?

Many English horoscope sites let you leave the birth time blank or quietly default to 12:00 PM noon. In traditional Four Pillars (BaZi), here is why that approach is misleading—and what to do instead:12

  1. Why Xiaodao Does Not Default to Noon: The Hour Pillar accounts for two of the eight characters in a BaZi chart (25% of the visible pillars), carrying Hidden Stems and elemental roots (tong gen). Even more importantly, if a birth occurred near midnight (23:00–01:00 local True Solar Time), the birth hour determines which Day Pillar and Day Master apply. Substituting a fake 12:00 PM (Wu Horse Hour) invents an unverified Hour Pillar. Likewise, do not click the "Current time" shortcut button as a stand-in for an unknown birth hour.
  2. Check Official Records or Family Context First: Before saving a profile, check your long-form birth certificate, hospital discharge baby book, or ask family members about concrete time markers (such as whether it was before sunrise, around a mealtime, or during a hospital shift change).
  3. Preview Candidate Hours Before Saving: If you know the birth occurred within a narrow window (for example, between 8:30 AM and 9:30 AM, straddling the 09:00 Chen–Si boundary), you can preview the four natal pillars and chart header for both candidate times as a guest in Cast a Bazi chart (viewing Luck Pillars, annual and monthly cycles, and the Timeline requires registering and saving a profile; when an entered time lands near a boundary, the page pops up a choice so you can confirm which side of the boundary to cast). Because saved profiles cannot be edited after creation (updating birth details requires deleting and recreating the profile, which uses a profile slot and deletes any generated reports on the old profile without refunding points), previewing candidate hours first keeps your saved profile clean.1

Frequently Asked Questions

A profile created via four-pillar reverse lookup is labeled "By Four Pillars"—it is not a complete profile with a verified birth time and has only the four pillars, so it cannot be used for a Bazi Report, Bazi Q&A, Daily Fortune, With-Bazi mode, or One-tap MBTI, and can only view the natal chart parts it displays.1 To use those features (which use Dao Points; see Membership & Dao Points for pricing) or to view Luck Pillars, annual and monthly cycles, and the Timeline after saving a profile, please create a "Complete" profile using the "Gregorian" or "Lunar" tab.

Cast a Chart by Date or Reverse-Lookup Known Four Pillars

Use Xiaodao's free BaZi Calculator to cast by Gregorian date, Lunar date, or "Pillars" reverse lookup across 1801–2099. Guests can preview the four natal pillars and chart header; register and save a complete profile to view Luck Pillars, annual and monthly cycles, and the Timeline, plus receive 200 Dao Points credited immediately upon first registration.

Cast a Bazi chartSample report

Sources

  1. 1

    Xiaodao, public FAQ (https://xiaodaox.com/en/guide/faq), checked October 22, 2026.

  2. 2

    Wan Minying, San Ming Tong Hui, volume 2, “论遁月时” and “论年月日时.” Classical 60-pillar cycle and stem–branch pairing rules.

Learn

Can You Look Up a BaZi Chart Directly by the Four Pillars or Without an Exact Birth Time?

Last updated: October 22, 2026

If you already have the eight characters of a chart (the Year, Month, Day, and Hour stem–branch pairs from a written reading or historical text) and want to find the matching calendar dates or view the chart structure, switch to the "Pillars" tab in Xiaodao's BaZi Calculator. The tool filters out invalid stem–branch combinations and searches 1801–2099 for matching time windows.

Keep two product boundaries in mind: first, a profile created via four-pillar reverse lookup is labeled "By Four Pillars"—it is not a complete profile with a verified birth time, has only the four pillars, and can only view the natal chart parts it displays (it cannot be used for Bazi Reports, Bazi Q&A, Daily Fortune, With-Bazi mode, or One-tap MBTI);1 second, when entering a birth by Gregorian or Lunar date, birth hour and minute are required, and Xiaodao does not substitute a fake noon time when the birth hour is unknown (guests can preview the four natal pillars and chart header; Luck Pillars, annual and monthly cycles, and the Timeline are available after registering and saving a complete profile).

How to Reverse-Lookup Dates from Known Four Pillars (1801–2099)

In the traditional sexagenary (Jia-Zi) calendar, Heavenly Stems and Earthly Branches only pair with matching polarity (Yang with Yang, Yin with Yin), the Month Stem is constrained by the Year Stem, and the Hour Stem is constrained by the Day Stem.2 Because the 60-year cycle and 60-day cycle repeat at different intervals, a given four-pillar combination only occurs during specific two-hour windows across a century.

To look up a chart by its pillars on Xiaodao:

  1. Select the "Pillars" Tab: Open Cast a Bazi chart and switch the calendar selector from "Gregorian" or "Lunar" to "Pillars".
  2. Select the Stems and Branches for Year, Month, Day, and Hour: As you pick each stem and branch, the selector automatically filters out impossible combinations so you cannot accidentally assemble an invalid chart (use "Clear" to reset your selections at any time).
  3. Choose a Matching Time Window: Xiaodao searches 1801–2099 and lists the matching date and time windows under "Matching Bazi" (if the Hour Branch is Zi, windows are labeled "Early Zi" or "Late Zi"; see BaZi 12 Two-Hour Branches Table). Select the matching window and click "Confirm" to view the natal chart.

(Note: If the search returns no matches, it means that combination does not occur within the 1801–2099 lookup window, not necessarily that the combination never existed in earlier historical centuries.)

Comparison: "Gregorian" vs. "Lunar" vs. "Pillars" Profiles on Xiaodao

A profile created via four-pillar reverse lookup is labeled "By Four Pillars"—it is not a complete profile with a verified birth time and has only the four pillars. Here is how Xiaodao's three profile input modes compare (guests can preview the four natal pillars and chart header; registering and saving a complete profile unlocks Luck Pillars, annual and monthly cycles, and the Timeline):1

Feature"Gregorian" Input"Lunar" Input"Pillars" Reverse Lookup
Supported Year Range1900 to present year1801–2099 (includes "This is a leap month" checkbox)1801–2099 reverse date-window lookup
Required InputsGregorian date, local clock hour & minute, sex, birthplaceLunar date (and leap-month status), local clock hour & minute, sex, birthplaceYear, Month, Day, and Hour stems/branches, sex, and selection of a matching window
True Solar Time & DSTAutomatically adjusted by birthplace and dateAutomatically adjusted by birthplace and dateNot applicable (no birthplace or exact clock minute)
Saved Profile Status Badge"Complete""Complete""By Four Pillars"
Free Chart ViewGuests preview 4 natal pillars & header; registering and saving a profile unlocks Luck Pillars, annual/monthly cycles & TimelineGuests preview 4 natal pillars & header; registering and saving a profile unlocks Luck Pillars, annual/monthly cycles & TimelineCan only view the natal chart parts it displays
One-tap MBTI (uses Dao Points)SupportedSupportedNot supported
11-Chapter Bazi Report & Bazi Q&A (Xuan-tier+, uses Dao Points)SupportedSupportedNot supported
Daily Fortune & With-Bazi Everyday Delights / Meeting (uses Dao Points)Supported (once profile has a Bazi Report)Supported (once profile has a Bazi Report)Not supported (Time-only Qimen readings remain available without a profile)

What If You Know Your Birth Date, But Not Your Birth Time?

Many English horoscope sites let you leave the birth time blank or quietly default to 12:00 PM noon. In traditional Four Pillars (BaZi), here is why that approach is misleading—and what to do instead:12

  1. Why Xiaodao Does Not Default to Noon: The Hour Pillar accounts for two of the eight characters in a BaZi chart (25% of the visible pillars), carrying Hidden Stems and elemental roots (tong gen). Even more importantly, if a birth occurred near midnight (23:00–01:00 local True Solar Time), the birth hour determines which Day Pillar and Day Master apply. Substituting a fake 12:00 PM (Wu Horse Hour) invents an unverified Hour Pillar. Likewise, do not click the "Current time" shortcut button as a stand-in for an unknown birth hour.
  2. Check Official Records or Family Context First: Before saving a profile, check your long-form birth certificate, hospital discharge baby book, or ask family members about concrete time markers (such as whether it was before sunrise, around a mealtime, or during a hospital shift change).
  3. Preview Candidate Hours Before Saving: If you know the birth occurred within a narrow window (for example, between 8:30 AM and 9:30 AM, straddling the 09:00 Chen–Si boundary), you can preview the four natal pillars and chart header for both candidate times as a guest in Cast a Bazi chart (viewing Luck Pillars, annual and monthly cycles, and the Timeline requires registering and saving a profile; when an entered time lands near a boundary, the page pops up a choice so you can confirm which side of the boundary to cast). Because saved profiles cannot be edited after creation (updating birth details requires deleting and recreating the profile, which uses a profile slot and deletes any generated reports on the old profile without refunding points), previewing candidate hours first keeps your saved profile clean.1

Frequently Asked Questions

A profile created via four-pillar reverse lookup is labeled "By Four Pillars"—it is not a complete profile with a verified birth time and has only the four pillars, so it cannot be used for a Bazi Report, Bazi Q&A, Daily Fortune, With-Bazi mode, or One-tap MBTI, and can only view the natal chart parts it displays.1 To use those features (which use Dao Points; see Membership & Dao Points for pricing) or to view Luck Pillars, annual and monthly cycles, and the Timeline after saving a profile, please create a "Complete" profile using the "Gregorian" or "Lunar" tab.

Cast a Chart by Date or Reverse-Lookup Known Four Pillars

Use Xiaodao's free BaZi Calculator to cast by Gregorian date, Lunar date, or "Pillars" reverse lookup across 1801–2099. Guests can preview the four natal pillars and chart header; register and save a complete profile to view Luck Pillars, annual and monthly cycles, and the Timeline, plus receive 200 Dao Points credited immediately upon first registration.

Cast a Bazi chartSample report

Sources

  1. 1

    Xiaodao, public FAQ (https://xiaodaox.com/en/guide/faq), checked October 22, 2026.

  2. 2

    Wan Minying, San Ming Tong Hui, volume 2, “论遁月时” and “论年月日时.” Classical 60-pillar cycle and stem–branch pairing rules.