Bazi to Gregorian Calendar Converter

Two directions between a date and four pillars

This converter handles a specific calendar task: enter a Gregorian date and clock time to see the corresponding year, month, day and hour pillars, or enter all four pillars and search a year interval for matching Gregorian dates. A pillar is a paired stem-and-branch designation; four pairs are called the Four Pillars or BaZi (Eight Characters). The reverse search returns matching candidates within the range you supply, rather than recovering a unique birth record.

The forward result also shows a Chinese lunar date and zodiac label, plus the stem-and-branch pair, Five-Phase names and Na Yin label for each pillar. These are separate traditional calendar or classification fields. In this English interface, some option labels and the Chinese calendrical values remain in Chinese script; they are not translated or interpreted as a personal reading.

How the traditional time labels fit together

The Hong Kong Observatory describes ten heavenly stems and twelve earthly branches, whose ordered pairings form the 60-part Gan-Zhi cycle. In the traditional twelve shichen system, each branch hour corresponds to a two-hour clock interval: for example, Si is 09:00–11:00 and Zi spans 23:00–01:00. The calendar relationship is not the same as simply assigning a modern month name to each pillar; solar terms are part of the traditional calendar framework.

The selector offers two late-Zi conventions for 23:00–24:00: one keeps the date's day pillar and one assigns the next day. Choose the same convention used by the record you are checking. This choice is a calculation setting, not a claim that one school is universally correct. Hong Kong Observatory: stems, branches and shichen hours and its overview of the 24 solar terms provide calendar background.

Convert a Gregorian birth time or search from pillars

1. For a forward conversion, enter the civil date and time

   Use the Gregorian date field and enter the recorded clock time. The result updates from those inputs. You can use the current-time control to fill the fields from the device clock, or clear the date and enter a different one.

2. Choose the late-Zi setting when it matters

   Select the convention that matches the source chart, especially when the time is between 23:00 and midnight. Keep the setting consistent when comparing two records; the interface names for these choices are displayed in Chinese.

3. Read each result field separately

   Check the Gregorian and lunar date, then the year, month, day and hour pillars. The Five-Phase pair and Na Yin value beneath a pillar are additional labels, not alternate spellings of the pillar itself. Copy the displayed record if you need to compare it with a source.

4. For reverse search, enter four pillars and a year interval

   Choose the year, month, day and hour Gan-Zhi pairs from the selectors, set start and end years, then run Search. The interface allows years from 1900 through 2100 and indicates a maximum interval of 61 years per search. Results list candidate Gregorian times and their Chinese lunar dates; copy the list to compare against independent records.

For example, entering 09:15 places the time within Si hour (09:00–11:00). The exact pillar output still depends on the selected calculation convention and calendar rules; use the result shown by the converter rather than inferring a complete chart from the hour label alone.

Questions about matching dates and boundary times

Limits to keep with the result

• Calendar scope: The forward inputs are Gregorian date and clock time; there is no direct lunar-date entry. If your source gives a lunar date, establish its Gregorian equivalent and any leap-month detail from a reliable calendar before entering it.
• Time and place: The form has no birthplace, time-zone, historical daylight-saving, or true-solar-time field. It uses the date and clock time entered, so a record from another time zone or near a shichen boundary may need its time basis checked separately.
• Traditional conventions: Calendar-year labels, solar-term boundaries and pillar conventions may differ in how they are applied. Near a boundary, preserve the selected late-Zi option and compare against a source using the same convention.
• Interpretation: This page converts and matches calendar fields. It does not provide a reading or evidence about personality, health, relationships, fortune or future events, and its output should not guide consequential personal decisions.
• Records: Use a birth document or original archive to confirm a historical date. Avoid including names or other identifying details when copying a result for discussion.