Meet Nhật Nguyệt: a Vietnamese lunar calendar, family reminders and a sourced library

Nhật Nguyệt is a lunar calendar and a library on Vietnamese festivals, customs and traditional divination arts, with lookup tools and an app that reminds the whole family of death anniversaries. Every number shows how it was worked out, and every article lists its sources at the end. The site is fully available in Vietnamese, English and Chinese.

Who is Nhật Nguyệt?

Nhật Nguyệt is a sourced knowledge library made for Vietnamese people at home and abroad, and for anyone curious about Vietnamese culture. Our assistant, Nhật Nguyệt AI, is an artificial intelligence and says so when asked. The editors and operators read every message sent to [email protected].

What does Nhật Nguyệt do?

A lunar calendar for every day: lunar date, sexagenary day, solar term, auspicious hours and the day's festivals. The calendar uses Vietnam time and is checked against astronomical data.
Lunar reminders for death anniversaries and full moons: set once, and the app converts to the solar date every year. Invite your family into a group and everyone gets the reminder.
33 lookup tools: date conversion, picking dates for an occasion, the Lỗ Ban ruler, Tử Vi and Bát Tự charts, numerology, prayer texts.
A knowledge library: articles on calendars, customs and traditional arts, arranged on a knowledge map so you can read from the basics up.
Nhật Nguyệt AI: ask in plain words; answers quote our articles with numbered sources.

There are also personal readings based on your chart on the web and in the Android app, written around each part of life.

Who is it for?

People who look after death anniversaries, full moons and Tết at home and want the whole family to remember.
People who want to know where a custom comes from and how regions differ, with sources they can check.
People learning Tử Vi, Bát Tự or the I Ching who want a correctly computed chart and the books of each school.

What do we hold to?

We say what kind of knowledge each thing is: calendar facts are calculations you can verify, customs are what people do and believe, and divination arts are the rules of one school, not tested. Every article carries a type label at the top, explained on the Types of knowledge page. What we got wrong and fixed is logged on the Corrections page. The app shows no ads, including the free version.