Find your day master

What a day master is

A BaZi or Saju chart is eight characters, set out as four pillars of two: one pillar for the year you were born, one for the month, one for the day, one for the hour. The upper character of the day pillar is your day master. In Chinese practice it is 日主 rizhu, in Korean practice 일간 ilgan, and both mean the same thing. It is the character that stands for you.

There are ten of them, made from the five elements in a yang and a yin form: Yang Wood through to Yin Water. That is a tenth of the population rather than a twelfth, which is not the point. The point is that a day master is never read alone. It is read against the season it landed in, against the seven other characters standing around it, and against the decade you happen to be in now. Two people who share a day master and nothing else read very differently.

Why the hour matters, and when it does not

Your day master comes from the date, so this tool asks for a time only because of what happens late at night. The day pillar here advances at 23:00 rather than at midnight, which is the older convention and the one the paid readings follow. If you were born between 23:00 and midnight, your day master is the one for the following day, and leaving the time blank will give you the wrong character.

Everything else the hour decides sits outside this tool. It places the hour pillar, and it is what a Zi Wei Dou Shu chart needs before its twelve palaces can be laid out at all.

What to do with the answer

One character is a starting point, not a reading. Three things turn it into one, and all three are free here.

1. Read your own stem in full. Each of the ten has its own page: what it is, how it reads in each season, and how it meets the other nine.
2. Draw the whole chart. The BaZi calculator adds the other three pillars, corrects for true solar time at your birth longitude, and translates every character.
3. Look up what you find. The reference library explains the terms a chart throws at you, one set at a time.

This tool sends nothing anywhere. The calculation runs in your browser, the date you type is never transmitted, and there is no account step.