True Solar Time Calculator

The longitude correction is four minutes per degree from the time-zone meridian. In western China on Beijing time, for example, the correction can exceed two hours.

The equation of time varies through the year between about −14 and +16 minutes because Earth's orbit is elliptical and tilted.

1. Enter birth date and clock time as recorded.
2. Select the birth city (not the current city).
3. The result shows the time-zone offset and any daylight saving in force.
4. Compare the true solar time with the hour boundaries.
5. Toggle clock time in Advanced settings to see the difference.

• Four pillars with stems, branches, pinyin and element colours.
• Hidden stems under each branch, with Ten Gods.
• Five-element count of visible characters, hidden stems listed separately.
• Combinations, clashes, harms and punishments found in the chart.
• Luck pillars with direction, exact starting age and calendar years.
• Annual pillar for any year, plus time-zone and solar-time details.

If the corrected time crosses an hour boundary, the hour pillar changes; if it crosses 23:00, the day may change too.

Daylight saving was used in China 1986–1991 and in many other countries; the calculator applies it from historical rules.

For a deeper explanation, see the guides.

All BaZi tools on this site share one calculation engine and the same settings, so results match across pages. These are the settings that can change a result:

Charts on this site use the published rule set: true solar time by default, the year changes at 立春 (Start of Spring), months change at the 12 节 solar terms and the day changes at 23:00. Example charts below are computed live by the same engine.

• True Solar TimeTrue solar time is clock time corrected for longitude (four minutes per degree from the zone meridian) and the equation of time (up to about ±16 minutes over the year).
• Hour PillarThe hour pillar covers one of twelve two-hour periods (时辰), starting with 子 at 23:00–01:00.
• Zi Hour (Rat Hour)The 子 hour runs 23:00–01:00.

The fastest way to understand True Solar Time Calculator is to look at real charts rather than memorise rules. Enter a birth date, time and city in the BaZi Calculator, then locate where True Solar Time Calculator appears: in a visible stem, hidden inside a branch, in the current luck pillar or in this year's annual pillar. Note the position, because the year pillar is usually read as background and early life, the month pillar as environment and career setting, the day pillar as the self and close partner, and the hour pillar as later life and output.

• Compare two or three charts where True Solar Time Calculator is prominent and two where it is absent; write down what differs in the overall balance.
• Check the month branch first: seasonal strength changes how much any factor matters.
• Use the hidden-stems and Ten Gods tables in the calculator output instead of guessing.
• Treat single factors as clues, never as verdicts; classical texts always weigh the whole chart.

Different schools describe True Solar Time Calculator with slightly different emphasis. This site follows widely used conventions (solar-term months, true solar time optional, Zi hour setting configurable) and states them openly so you can compare results with a book or another calculator.

True Solar Time Calculator is one piece of a larger system. If you are learning BaZi from scratch, the order below builds each idea on the previous one, and every step links to free reference pages on this site.

1. Calculate a chart and confirm the four pillars are correct (checklist).
2. Learn the ten heavenly stems and twelve earthly branches.
3. Find your Day Master and judge its strength with the five elements.
4. Read the Ten Gods in context.
5. Move on to timing with luck and annual pillars.
6. Use the glossary whenever a term is unfamiliar.

BaZi is a traditional cultural system. This page explains how the symbols are defined and read; it does not make scientific claims or predictions about your health, money or relationships.