Sajuby sajusaju

Free · no account

Koreans don’t ask your star sign.
They ask your birth hour.

A Korean birth chart — saju — is built from four pillars: your year, month, day and hour. The upper character of the day pillar is your Day Master, the character that stands for you. Where a sun sign is one of twelve, a Day Master is one of ten. Enter your birth details and see all eight characters, free.

The hour decides one of your four pillars — the same way your rising sign needs it.

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Used only to place your ten-year cycles — it does not change your Day Master.

We apply the historical time zone and daylight saving rules for that exact date.

No account, no email, no payment. We don’t store what you type here.

How this is calculated

A chart is arithmetic before it is interpretation. Your birth moment is converted to the local time actually in force at your birthplace on that date — including historical daylight saving, which many calculators skip — and then corrected toward true solar time using your city’s longitude.

That correction is not cosmetic. A birth near midnight, or during a summer-time period that no longer exists, can land on a different hour pillar entirely. If your chart here differs from another site’s, this is almost always why.

Frequently Asked Questions

What is a Day Master?

Your Day Master is the character that stands for you in your own chart — the upper character of your day pillar. Where a sun sign is one of twelve, a Day Master is one of ten, and it is drawn from the day you were born rather than the month.

Why do you need my birth hour?

One of the four pillars is built from the hour. It is the same reason your rising sign needs an exact birth time in Western astrology. You can still get three pillars and your Day Master without it.

Why does my chart differ from another site's?

Usually the birth hour. A chart has to be built in the local time actually in force where and when you were born, including historical daylight saving. Many calculators apply today's rules, or skip the correction entirely, which can shift the hour pillar by one position.

Is this the same as Chinese BaZi?

The eight characters are the same tradition of the Four Pillars. Saju is the Korean lineage of it, with its own interpretive conventions. Neither is a translation of the other.

Is the calculator really free?

Yes. There is no account, no email and no payment. The paid reading is the interpretation — what your chart means, your ten-year cycles and the year ahead.

For entertainment and self-reflection — not medical, legal or financial advice.

What the ten Day Masters mean →Get the full reading →