Frequently asked questions
This site uses your birth date and time to work out your Mệnh (Nạp Âm element), Four Pillars, Tử Vi chart, daily fortune and zodiac matches. These are the questions people ask most when they want to know how something is calculated or when a result looks different from what they expected. The guide pages go into each topic in more depth.
I was born in January. Why is my zodiac sign from the previous year?
The zodiac sign and Mệnh change at the Lunar New Year (Tết), not on 1 January. Tết moves each year between late January and mid-February, so if you were born before it, the previous year's sign and Mệnh are correct. The site calculates the date of Tết from the lunar calendar of your country of birth.
My Four Pillars year is sometimes different from my zodiac sign. Is that a bug?
No. The year pillar in the Four Pillars changes at Lập Xuân, the start of spring (around 4 February, when the sun reaches 315° longitude), not at Tết, and the month pillars follow the solar terms too. So if you were born between Tết and Lập Xuân, your zodiac sign (counted from Tết) and your year pillar (counted from Lập Xuân) can belong to different years. The two systems simply count the year differently, and both results are correct.
Can I use the site without knowing my birth time?
Yes. Enter only your birth date and the site runs in simple mode: you still get your Mệnh, the year, month and day pillars, the daily fortune and zodiac matches. The hour pillar, the Tử Vi chart and its reading need a birth time, so they are not shown. Simple mode calculates from noon on that day, so if you were born on the day a solar term changes, your month pillar may be off. You can add your time, country and gender later to see everything.
Why does the country of birth matter?
There are three reasons. First, each country's lunar calendar uses its own time zone (Vietnam UTC+7, China UTC+8, Korea and Japan UTC+9), so the first day of a month or Tết can differ by a day. Second, past daylight saving time and time zone changes are applied for that country. Third, clock time is converted to local mean solar time using the capital's longitude to find your two-hour birth period. In Hanoi solar time runs only about three minutes ahead of the clock, but in Seoul it runs almost half an hour behind.
I was born after 11 pm. Which day counts?
The first two-hour period of the day, the Rat (Tý) hour, runs from 11 pm to 1 am, so a birth after 11 pm in solar time counts as the Rat hour of the next day. The site then builds the Tử Vi chart and the day pillar from the next day, and the result screen shows which date was used. Because of the solar-time correction, a birth just after 11 pm on the clock may still fall in the previous day's Pig hour, so check the hour shown in your result.
I was born in a leap month. What are the two options?
Every few years the lunar calendar repeats a month, called a leap month. Tử Vi needs your birth month to place the Life palace, and schools handle leap months differently. The default, "As the regular month", treats the whole leap month as that month; "Day 16 on = next month" keeps days 1 to 15 in that month and counts day 16 onward as the following month. Your year and day stay the same and only the month used for the chart changes, so you can compare both and see which one resonates.
What is the difference between Tử Vi, the Four Pillars and Mệnh?
Mệnh is the Nạp Âm element of your birth year's stem-branch, so everyone born in the same year shares it. The Four Pillars (Bát Tự) use the eight characters of your year, month, day and hour to look at the balance of the five elements and your day master. Tử Vi builds a chart from your lunar birth date, hour and gender, placing stars in 12 palaces that each describe an area of life. Put simply, Mệnh is the simplest and Tử Vi the most detailed.
How is the daily fortune score calculated?
The base score comes from how the day's Nạp Âm element relates to your Mệnh element: highest when the day produces your element, then the same element, then an element you control, then one you produce, and lowest when the day controls you. Points are added if the day's branch forms a pair or trio with your zodiac sign and taken away for a clash, and a small daily variation gives a final score between 40 and 99. Health, love, money and work are adjusted in their own ways, with bonus points on Peach Blossom, Prosperity and Travelling Horse days. The same person on the same date always gets the same result.
Why does my fortune text look similar two days in a row?
The Nạp Âm pairs up consecutive stem-branches, so the day's element usually stays the same for two days. The element-based text can therefore repeat for two days, while the score changes slightly because of the branch relationship and the daily variation. On the third day the element changes, and so does the mood of the reading.
How is the match percentage calculated?
Only the two lunar birth years are used. The score starts at 72 and goes up or down with the zodiac relationship (harmony trios and pairs add, harms and clashes subtract), the heavenly stems (a stem combination adds, a controlling pair subtracts) and the Nạp Âm elements (generating adds, the same element adds a little, controlling subtracts), and is shown between 55% and 99%. It never goes below 55%. A zodiac match is a fun reference; a relationship is what two people build together.
What information do you store?
If you are not signed in, your name, birth date and time are calculated in your browser and not sent to our server. If you sign in with Google and save your details, we store your birth date, time, country, gender and nickname, and you can delete them or your whole account at any time (your Google account number is kept only as an irreversible hash; we never receive your email, name or photo). Match maps store only a nickname, birth year (zodiac sign) and match score; the birth date is stored only if a friend chooses to show it to the map owner, and only the owner can see it. Groups store just a nickname and lunar birth year, and others see only the nickname, sign and score. Birthday cards keep the birth date on the server for 30 days to calculate the fortune and the link never shows it, while sending the card as an image saves nothing at all.
How accurate is it?
We work hard to calculate the traditional calendar and rules correctly, but the readings themselves come from an old cultural system of symbols. Enjoy them as a light way to start the day or something to chat about. Please make important decisions about health, money, marriage or career with professional advice and your own judgement, not a fortune reading.