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True solar time in BaZi
Why clock time and “sun time” are not the same, why this free site does not correct for it, and how a simple longitude sketch works — without collecting a birth date.
At a glance. True solar time adjusts civil clock time so that midday is when the sun is highest at that place. In BaZi this can move the hour pillar, and sometimes the day pillar near 23:00–01:00. The Element Check does not apply this correction; the Written Reading does, from your birth city. Last update: 2026-11-12.
Most of us live by standard time: a whole zone that shares one clock, often on a meridian 15° of longitude apart from its neighbours. The sun does not obey zone borders. When it is noon on the official clock in a city west of the zone meridian, the sun may still be a little east of the meridian; east of the meridian, the sun may already have passed the highest point.
A common teaching rule is simple: about four minutes of clock time for every degree of longitude away from the meridian your time zone is built on. (A fuller astronomical correction also uses the equation of time through the year. That belongs in a careful reading, not in this sketch.)
Try the idea (longitude only)
Enter a longitude in degrees. Nothing else is asked, and nothing is sent. You will see an approximate offset from a meridian you choose. This is a teaching aid, not a chart and not a conversion of anyone’s birth time.
What this changes in a chart — and what it does not
- May change: the hour pillar, if the corrected time crosses a two-hour boundary. Rarely, the day pillar, if you were born close to the 23:00–01:00 convention some schools use.
- Does not change by itself: who you are, what will happen, or whether a decision is “lucky.” It is a more careful way of writing the time.
- Still needs a city: daylight-saving rules, historical zone changes, and the equation of time are not in this sketch. The Written Reading takes the birth city into account; this page does not ask for it.
If the Element Check warns that your date sits on a solar-term boundary, or that an entered clock time is close to an hour edge, that is the moment a solar-time correction is most worth doing properly — not by guessing a number here.
The free check runs in your browser and does not send your birth date. Reflective, not predictive.
Questions
- What is true solar time in BaZi?
- Clock time corrected so that noon is when the sun is highest at the birth place. TangoEra applies this in the Written Reading, not in the free Element Check.
- Why does the free check ignore it?
- So the check can stay on your device with only a calendar date. A careful correction needs a place.
- Is this sketch enough to time a chart?
- No. It only illustrates about four minutes per degree from a meridian.
- Does it predict events?
- No.
Keep learning: Day Master · Four Pillars explained · How to choose a reading.