Open data
Download the reference tables as CSV
Every reference table on Nhật Nguyệt is generated by the same engine that powers the tools, so the numbers here and the numbers a tool returns are the same numbers. The 33 datasets below, 168,267 rows in all, download as CSV for reuse.
The same data is also on Hugging Face, with bilingual dataset cards, and on GitHub, with runnable Python and JavaScript examples and a document naming where the schools disagree.
Data release ID 2026.10.27-cd6fca71, generated 2026-10-27. Manifest: manifest.json. DOI: 10.5281/zenodo.23009396. Checks behind this release
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
Cite as: Nhật Nguyệt (2026). The ten heavenly stems (version 1.1.1, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/10-thien-can
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
Cite as: Nhật Nguyệt (2026). Compatibility matrix of the 12 earthly branches (version 1.2.0, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/12-con-giap-hop-khac
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
Cite as: Nhật Nguyệt (2026). The twelve earthly branches (version 1.1.1, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/12-dia-chi
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
Cite as: Nhật Nguyệt (2026). The twelve day officers (Thap Nhi Truc) (version 1.2.0, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/12-truc
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
Cite as: Nhật Nguyệt (2026). The 22 Major Arcana of the Tarot (version 1.1.1, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/22-an-chinh-tarot
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
Cite as: Nhật Nguyệt (2026). The 24 solar terms (version 1.1.1, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/24-tiet-khi
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
Cite as: Nhật Nguyệt (2026). The 56 Minor Arcana cards (version 1.1.1, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/56-an-phu-tarot
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
Cite as: Nhật Nguyệt (2026). Sexagenary cycle table (60 Hoa Giap) (version 1.1.1, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/60-hoa-giap
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
Cite as: Nhật Nguyệt (2026). The 64 hexagrams of the I Ching (version 1.1.1, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/64-que-kinh-dich
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
Cite as: Nhật Nguyệt (2026). The nine presiding stars (Cuu Dieu) (version 1.2.0, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/9-sao-chieu-menh
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
Cite as: Nhật Nguyệt (2026). Zodiac sign boundaries year by year, 1950 to 2050 (version 1.1.5, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/bien-cung-hoang-dao-1950-2050
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
An EVALUATION dataset, not knowledge content: these are questions used to measure the site's search box, with known correct answers. The questions and answers are not the site's claims about the topics asked.
Cite as: Nhật Nguyệt (2026). Retrieval evaluation set for Vietnamese folk belief and calendar (version 1.2.0, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/cau-hoi-danh-gia-tim-kiem
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
Cite as: Nhật Nguyệt (2026). Letter to number tables, Pythagorean and Chaldean (version 1.1.2, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/chu-sang-so-than-so-hoc
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
Cite as: Nhật Nguyệt (2026). Kua number and Bat Trach directions (version 1.2.2, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/cung-phi-bat-trach
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
Cite as: Nhật Nguyệt (2026). Where the schools disagree (version 1.4.0, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/diem-bat-dong-giua-cac-phai
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
Cite as: Nhật Nguyệt (2026). Auspicious hours across the sixty-day stem-branch cycle (version 1.1.1, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/gio-hoang-dao-60-ngay
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
Cite as: Nhật Nguyệt (2026). The sixty stem-branch pairs crossed: sounds, harmony, clash and element relation (version 1.1.2, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/hoa-giap-ghep-cheo
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
Cite as: Nhật Nguyệt (2026). Questions and answers on Vietnamese offering rites (version 1.0.2, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/hoi-dap-le-cung
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
Cite as: Nhật Nguyệt (2026). Things to avoid and practical notes for Vietnamese offering rites (version 1.0.2, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/kieng-ky-luu-y-le-cung
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
Cite as: Nhật Nguyệt (2026). Vietnamese festivals mapped to solar dates, 2026 to 2030 (version 1.4.0, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/le-hoi-quy-doi-ngay-duong
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
Cite as: Nhật Nguyệt (2026). Festivals and folk beliefs of the 54 ethnic groups of Vietnam (version 1.1.1, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/le-hoi-tin-nguong-theo-dan-toc
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
Cite as: Nhật Nguyệt (2026). Vietnamese festivals, seasonal feasts and public holidays (version 1.5.0, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/le-hoi-viet-nam
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
Cite as: Nhật Nguyệt (2026). Vietnamese ritual offerings (version 1.0.1, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/le-vat-cung-viet-nam
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
Cite as: Nhật Nguyệt (2026). Vietnamese lunisolar calendar, 1900 to 2100 (version 1.2.2, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/lich-am-duong-1900-2100
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
Cite as: Nhật Nguyệt (2026). Types of Vietnamese offering rites (version 1.6.0, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/loai-le-cung-viet-nam
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
Cite as: Nhật Nguyệt (2026). Start moments of the 24 solar terms, 1900 to 2100 (version 1.2.4, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/moc-tiet-khi-1900-2100
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
Cite as: Nhật Nguyệt (2026). Folk inauspicious days mapped onto solar dates, 2026 to 2035 (version 1.1.1, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/ngay-ky-dan-gian-2026-2035
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
Cite as: Nhật Nguyệt (2026). Vietnamese offering procedures (version 1.6.0, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/nghi-thuc-cung-viet-nam
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
Cite as: Nhật Nguyệt (2026). Daily hexagram by the Gua Qi method, 1900 to 2100 (version 1.2.1, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/que-ngay-quai-khi-1900-2100
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
Cite as: Nhật Nguyệt (2026). Tam Tai, Kim Lau and Hoang Oc by birth year and year in question (version 1.2.0, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/tam-tai-kim-lau-hoang-oc
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
Cite as: Nhật Nguyệt (2026). Order of the sixty Gua Qi hexagrams (version 1.3.1, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/thu-tu-60-que-quai-khi
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
Cite as: Nhật Nguyệt (2026). Segments of the three Lo Ban rules (version 1.2.0, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/thuoc-lo-ban
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
Cite as: Nhật Nguyệt (2026). Vietnamese offering prayers (văn cúng) (version 1.5.0, data release 2026.10.27-cd6fca71) [Data set]. CC BY 4.0. DOI 10.5281/zenodo.23009396. https://nhatnguyet.org/en/bang/van-cung-viet-nam
Checks behind this release
- New moons (where lunar months begin) against NASA: 2,474 instants, mean absolute error 1.1 min, P95 2.5 min, max 3.9 min (the test allows up to 5 min).
- Winter solstice of the Gua Qi method against IMCCE: 201 instants, mean absolute error 3.9 min, P95 9.2 min, max 12.3 min (the test allows up to 15 min).
- Solar term moments against IMCCE: 4,824 instants, mean absolute error 4.2 min, P95 9.7 min, max 14.4 min (the test allows up to 15 min).
- Solar term moments against USNO: 804 instants, mean absolute error 4.3 min, P95 10 min, max 13 min (the test allows up to 15 min).
- 4 date comparisons with a calendar rebuilt independently from NASA, IMCCE, USNO data: 50 differences, each listed in ngoai-le-doi-chieu.csv.
- 23 of 33 datasets have invariant checks; 5 have no content check yet.
- oracle.csv (6.5 MB): sample dates with expected values, for re-running the tool-against-table comparison on the public API.
Licence and attribution
Everything above is released under CC BY 4.0: reuse commercially, adapt freely, attribution is all that is asked. The minimum attribution line:
Source: Nhật Nguyệt (nhatnguyet.org), CC BY 4.0
The content of these tables is traditional knowledge in the public domain; the licence here covers the work of compiling, cross-checking and rendering it into a machine-usable form.
This dataset records cultural and calendrical conventions, not scientific claims. It is suitable for cultural research, NLP, and calendar applications. It is not intended for predicting events, evaluating people, or making decisions that affect anyone.