Open data

Reference tables

The tables the tools on Nhat Nguyet look things up in, laid out in full. The same computation gives the same answer to anyone who runs it.

33 tables, 168,267 rows, released under CC BY 4.0. Each table has a CSV to download, a description of every column, and a notes column that says where the schools disagree rather than quietly picking a side.

• The ten heavenly stems

  The ten heavenly stems with the five-element attribution and yin-yang polarity of each.

  10 rows · 8 columns · version 1.1.1, last changed 2026-09-30

• Compatibility matrix of the 12 earthly branches

  The relation between every pair of the 12 earthly branches, 144 rows, in long form with one pair per row.

  144 rows · 8 columns · version 1.2.0, last changed 2026-10-27

• The twelve earthly branches

  The twelve earthly branches with their zodiac animal, five-element attribution and two-hour window.

  12 rows · 9 columns · version 1.1.1, last changed 2026-09-30

• The twelve day officers (Thap Nhi Truc)

  The twelve day officers in cycle order, with their meaning and the tasks each day suits or avoids.

  12 rows · 9 columns · version 1.2.0, last changed 2026-10-04 · the tool that uses it

• The 22 Major Arcana of the Tarot

  The Major Arcana with Vietnamese and English names, keywords, and upright and reversed meanings.

  22 rows · 10 columns · version 1.1.1, last changed 2026-09-30

• The 24 solar terms

  The solar date each of the 24 terms begins, for every year from 2020 to 2035, computed from solar longitude in Vietnam time.

  384 rows · 10 columns · version 1.1.1, last changed 2026-09-30

• The 56 Minor Arcana cards

  The complete Minor Arcana across four suits, with Vietnamese and English names, keywords, upright and reversed meanings. Together with the existing 22 Major Arcana it makes the full 78-card deck.

  56 rows · 10 columns · version 1.1.1, last changed 2026-09-30 · the tool that uses it

• Sexagenary cycle table (60 Hoa Giap)

  All 60 stem-branch pairs with their Na Yin five-element attribution and the lunar years they cover between 1924 and 2043.

  60 rows · 11 columns · version 1.1.1, last changed 2026-09-30

• The 64 hexagrams of the I Ching

  All 64 hexagrams in King Wen order, with Vietnamese and Han names, upper and lower trigrams, and the image.

  64 rows · 11 columns · version 1.1.1, last changed 2026-09-30 · the tool that uses it

• The nine presiding stars (Cuu Dieu)

  The nine stars with their classification, reading, and the lunar ages they fall on, listed separately for men and women.

  9 rows · 8 columns · version 1.2.0, last changed 2026-10-04

• Zodiac sign boundaries year by year, 1950 to 2050

  The date and time the sun enters each zodiac sign, computed per year instead of using a fixed boundary.

  1,212 rows · 11 columns · version 1.1.5, last changed 2026-09-30 · the tool that uses it

• Retrieval evaluation set for Vietnamese folk belief and calendar

  1,194 questions in Vietnamese, English and Chinese, each with the slug of the article that answers it where one exists. Built to measure search ranking, not to be read. Three groups: questions taken from in-article FAQ blocks (with a gold answer), real search demand collected from the web (no gold answer), and tool names.

  1,194 rows · 9 columns · version 1.2.0, last changed 2026-09-30 · the tool that uses it

• Letter to number tables, Pythagorean and Chaldean

  The numeric value of each letter in both numerology systems, with the convention for Vietnamese diacritics and the letter D with stroke.

  33 rows · 7 columns · version 1.1.2, last changed 2026-10-27 · the tool that uses it

• Kua number and Bat Trach directions

  Kua number by birth year and sex for 1900 to 2099, with the four favourable and four unfavourable directions.

  400 rows · 10 columns · version 1.2.2, last changed 2026-10-27 · the tool that uses it

• Where the schools disagree

  Each point where Vietnamese calendrical, feng shui and divination sources disagree, with the reading taken here, the competing reading still in circulation, and what changes when you compare two sources. Every reference table has to pick one; most pick and say nothing.

  27 rows · 24 columns · version 1.4.0, last changed 2026-10-27 · the tool that uses it

• Auspicious hours across the sixty-day stem-branch cycle

  The twelve double-hours of each day across the sixty-day stem-branch cycle, marking which are auspicious. Sixty times twelve is seven hundred and twenty rows, one full cycle.

  720 rows · 8 columns · version 1.1.1, last changed 2026-09-30 · the tool that uses it

• The sixty stem-branch pairs crossed: sounds, harmony, clash and element relation

  Every pair among the sixty stem-branch combinations, three thousand six hundred rows, giving the element relation between their sounds and the branch grouping.

  3,600 rows · 12 columns · version 1.1.2, last changed 2026-10-27 · the tool that uses it

• Questions and answers on Vietnamese offering rites

  158 questions and answers on 44 types of Vietnamese offering rites, in three languages: questions readers actually ask (dates and times, offerings, how the rite is done, regional differences) and answers according to the sources, with the source page addresses. Only reviewed entries are included.

  158 rows · 16 columns · version 1.0.2, last changed 2026-10-21 · the tool that uses it

• Things to avoid and practical notes for Vietnamese offering rites

  132 things to avoid and practical notes for Vietnamese offering rites, across 38 rite types, one sentence per row in three languages with the rite, region, tradition, type and source page addresses. Taken only from reviewed procedure rows; it describes custom according to the sources and prescribes nothing.

  132 rows · 22 columns · version 1.0.2, last changed 2026-10-21 · the tool that uses it

• Vietnamese festivals mapped to solar dates, 2026 to 2030

  The actual solar date of each festival across five years, with the weekday. Lunar festivals land on a different solar date every year, and this table works that out in advance.

  790 rows · 14 columns · version 1.4.0, last changed 2026-10-19 · the tool that uses it

• Festivals and folk beliefs of the 54 ethnic groups of Vietnam

  Festivals, rites and worship customs of the 54 ethnic groups of Vietnam, one row per festival, with each group's home region and language family. Extracted from 54 Nhật Nguyệt articles; every row cites the article it came from.

  187 rows · 13 columns · version 1.1.1, last changed 2026-09-30 · the tool that uses it

• Vietnamese festivals, seasonal feasts and public holidays

  Vietnamese folk festivals, seasonal feasts and public holidays, each with its fixed lunar or solar date.

  200 rows · 23 columns · version 1.5.0, last changed 2026-10-19 · the tool that uses it

• Vietnamese ritual offerings

  A catalogue of 232 Vietnamese ritual offerings, from incense, flowers, betel, sticky rice and cakes to meat dishes, votive paper and objects, gathered from the offering names in the procedure rows: names in three languages, other names, group, vegetarian or not, the components of combined trays, and the number of procedure rows and rites using each item. It is the key table for the ma_le_vat column of the nghi-thuc-cung-viet-nam dataset.

  232 rows · 16 columns · version 1.0.1, last changed 2026-10-21 · the tool that uses it

• Vietnamese lunisolar calendar, 1900 to 2100

  Every solar day from 1900 to 2100 with its lunar date, leap month flag, day and year stem-branch, the solar term in force and the day officer.

  73,414 rows · 16 columns · version 1.2.2, last changed 2026-10-04 · the tool that uses it

• Types of Vietnamese offering rites

  155 types of Vietnamese offering rites in 15 groups, from ancestor and death-anniversary rites, Tết and the festivals of the year to funerals, communal houses and temples, and the rites of ethnic communities; each with alternative names, timing, recipients, a short description, classification axes (cycle, social setting, beings worshipped, tradition, ethnic group, cultural region), a structured date and sourced passages on its customs. It is the key table for Nhật Nguyệt's datasets on offering prayers and rite customs.

  155 rows · 50 columns · version 1.6.0, last changed 2026-10-21 · the tool that uses it

• Start moments of the 24 solar terms, 1900 to 2100

  The start moment of each solar term across 201 years in Vietnam time, with the solar longitude of the mark and a flag for moments falling close to midnight.

  4,824 rows · 15 columns · version 1.2.4, last changed 2026-09-30 · the tool that uses it

• Folk inauspicious days mapped onto solar dates, 2026 to 2035

  Every solar day across ten years, showing whether it falls on Tam Nuong, Nguyet Ky, Sat Chu or Tho Tu, with the lunar date and stem-branch for checking.

  3,652 rows · 15 columns · version 1.1.1, last changed 2026-09-30 · the tool that uses it

• Vietnamese offering procedures

  407 rows of offering procedures: each row is how one rite is performed in one region within one tradition, with timing, place of offering, officiant, offerings with catalogue codes, order of steps, things to avoid and practical notes, plus the addresses of the source pages or the titles of source books. Where sources disagree is recorded in the ghi_chu column.

  407 rows · 58 columns · version 1.6.0, last changed 2026-10-21 · the tool that uses it

• Daily hexagram by the Gua Qi method, 1900 to 2100

  Every solar day from 1900 to 2100 with its ruling hexagram under the Gua Qi method (six days seven parts), the line ruling the day, the position in the sixty-hexagram cycle, the winter solstice anchor and the minutes elapsed since it, the solar term and the cardinal hexagram line for that term. Enough to recompute every row independently.

  73,414 rows · 19 columns · version 1.2.1, last changed 2026-09-30 · the tool that uses it

• Tam Tai, Kim Lau and Hoang Oc by birth year and year in question

  Every birth year from 1940 to 2010 crossed with every year in question from 2020 to 2050, showing whether the pair falls under Tam Tai, Kim Lau or Hoang Oc, with the arithmetic shown.

  2,201 rows · 13 columns · version 1.2.0, last changed 2026-10-04 · the tool that uses it

• Order of the sixty Gua Qi hexagrams

  The sixty hexagrams that take turns ruling the days under the Gua Qi method, in order from Inner Truth at the winter solstice, with their solar month, their rank (duke, sovereign, marquis, grand master, minister) and when each takes over counted from the solstice. The lookup table for the que-ngay-quai-khi-1900-2100 dataset.

  60 rows · 19 columns · version 1.3.1, last changed 2026-09-30 · the tool that uses it

• Segments of the three Lo Ban rules

  The favourable and unfavourable segments on all three Lo Ban rules, with the millimetre range each segment covers in one cycle.

  26 rows · 15 columns · version 1.2.0, last changed 2026-10-06 · the tool that uses it

• Vietnamese offering prayers (văn cúng)

  456 prayers, orations, petitions and repentance verses in use, in print and online in Vietnam, one text per row with its rite type, part of the rite, region, tradition, text family, variants and fill-in slots. The wording is kept in Vietnamese as the source gives it; 348 texts carry the name and address of the source page, 108 are collected texts whose source is not named.

  456 rows · 44 columns · version 1.5.0, last changed 2026-10-21 · the tool that uses it