Pivot Clock
Tianshu · the pivot star of the Big Dipper
Tianshu is the first star of the Big Dipper; the ancients watched the Dipper to tell the seasons and the hours. Here the Chinese stem-and-branch calendar and the stars come together.
Your natal chart and Four Pillars from the birth details saved in your account, and a live clock that relates the present moment to them.
A reference for traditional culture and self-observation. Nothing here predicts events or tells good from bad fortune, and it is not medical, legal, financial or investment advice.
What is this? An introduction to BaZi, the natal chart and the Pivot Clock
BaZi in one minute
BaZi (八字, “eight characters”), also called the Four Pillars of Destiny, is a traditional Chinese way of describing a moment in time. Its roots in the Chinese calendar reach back well over a thousand years, and the method practised today took shape gradually over many centuries.
The calendar counts time with two sets of signs: 10 Heavenly Stems (天干) and 12 Earthly Branches (地支). Paired in order they form a cycle of 60 combinations, which is used for years, months, days and two-hour periods alike.
Your birth moment is written as four pillars — year, month, day and hour — each one stem over one branch: four pillars of two characters make the eight characters. The stem of your day pillar is your Day Master. In the tradition it stands for you, and every other character is read in relation to it.
The Five Elements
Every stem and branch belongs to one of five elements, or phases: Wood, Fire, Earth, Metal and Water. They relate in two cycles. Generating: Wood feeds Fire, Fire leaves Earth (ash), Earth bears Metal, Metal carries Water, Water nourishes Wood. Controlling: Wood parts Earth, Earth dams Water, Water quenches Fire, Fire melts Metal, Metal cuts Wood. Seen from your Day Master, these relations give the “Ten Gods”: labels such as Resource, Output or Wealth for each of the other characters.
Months and hours follow the sun
BaZi months are not lunar months. They follow the 24 solar terms (节气), set by the sun’s position along the ecliptic, and the year pillar changes at Lichun (立春, the Beginning of Spring, around 4 February). The hour is traditionally read from the sun too, so this page can use true solar time: your clock time corrected for longitude and for the time of year. Luck pillars (大运) are ten-year phases counted from the month pillar; they describe the slow background rhythm of a life.
The Western natal chart
The natal chart from Western astrology shows where the Sun, Moon and planets stood along the zodiac at your birth, seen from your birthplace, together with the Ascendant and the twelve houses. This page uses the tropical zodiac and Placidus houses.
How the Pivot Clock combines them
BaZi gives the rhythm of time: the current hour and day each have a pillar, and the clock shows how they meet your chart — which element they bring, which Ten God they are to your Day Master, and whether branches combine or clash. Astrology gives the sky: today’s transits, where the planets are now compared with your natal planets. Together they work like a weather report for self-observation, not a forecast of events.
Why “Tianshu”?
Tianshu (天枢, “celestial pivot”) is the traditional Chinese name of Dubhe, the first star of the Big Dipper. A well-known classical saying ties the direction of the Dipper’s handle to the seasons — east in spring, south in summer, west in autumn, north in winter — and the Dipper turning around the pole served as a clock in the sky. The name suits a clock that joins the calendar and the stars.
Glossary
| Term | Meaning |
|---|---|
| Heavenly Stem 天干 | One of 10 signs (甲 乙 丙 丁 戊 己 庚 辛 壬 癸), each with an element and a yin or yang side. |
| Earthly Branch 地支 | One of 12 signs (子 丑 寅 卯 辰 巳 午 未 申 酉 戌 亥), also used for the 12 two-hour periods and the zodiac animals. |
| Pillar 柱 | A stem over a branch, for the year, month, day or hour. |
| Day Master 日主 | The stem of your day pillar: the reference point of the chart. |
| Ten Gods 十神 | The ten ways any stem can relate to your Day Master (Friend, Resource, Output, Wealth, Officer and their pairs). |
| Five Elements 五行 | Wood, Fire, Earth, Metal and Water, with their generating and controlling cycles. |
| Luck Pillar 大运 | A ten-year phase that sets the long background rhythm. |
| Shichen 时辰 | One of the 12 traditional two-hour periods, named after the branches (子时 = 23:00–01:00). |
How to use it
Glance at it the way you would at a weather report. Notice the current hour and day, read the suggestions and open “Why” to see the rule behind each one, then compare it with your own experience. If something resonates, take it as a prompt for reflection or practice; if not, let it go. The Pivot Clock does not predict events, and it is not medical, legal, financial or investment advice.
Cargando tu cuenta…
Sign in to see your own chart
Your chart is computed from the birth details saved in your account and is visible only to you. You can also look at a sample first, without signing in.
Add your birth details first
Enter your date, time (or “unknown”) and place of birth under “Saved birth details” on your account page. Gender is optional and only sets the direction of the 10-year luck pillars.
On: the day and hour pillars use local apparent solar time at the birthplace (longitude and equation of time). Off: standard clock time, with any daylight-saving hour removed. Year and month pillars always change at the exact solar term (节气).
Pivot Clock · now
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Relations to your chart
Today’s transits
Sky & You
Your natal chart meets the sky of the selected shichen. Rule-based prompts for practice and self-observation — not predictions. Open “Basis” for the aspect, orb and timing behind each line.
No birth time saved: houses, Ascendant / MC and the chart ruler are left out, and the natal Moon is not used (it can be off by several degrees).
How these are picked
- Layers: this shichen = the transiting Moon and the current Ascendant / MC (computed for your birthplace); today = Sun, Mercury, Venus, Mars; this period = Jupiter to Pluto, only to your personal points (Sun, Moon, Mercury, Venus, Mars, Ascendant, MC, chart ruler).
- Major aspects only. Orbs: Moon, Sun, Mercury, Venus 2.5°; Mars, Jupiter, Saturn 2°; Uranus, Neptune, Pluto 1.5°. The Ascendant / MC count when they cross a natal point inside the shichen.
- Ranking: natal-point weight × orb tightness × aspect weight, with applying contacts ahead of separating ones; the chart ruler (traditional ruler of your Ascendant sign) gets extra weight. At most two lines per layer for the shichen and today, one for the period, five in all; the Sun / Moon houses fill in when there are fewer than three.
- Hard aspects (square, opposition) are read as tension to notice, not as a judgement. Moon void of course = the Moon makes no further major aspect before changing sign.
- The BaZi line appears only when the strongest element of this moment’s pillars and the element of the Moon’s sign point the same way: Earth / Metal with an earth sign (steady), Fire / Wood with a fire sign (outward), Water with a water sign (inward).
Suggestions for practice and reflection
Rule-based and transparent: open “Why” to see the rule behind each line. Treat them as prompts for self-observation, not instructions.
子时 convention: 23:00–01:00 is one 时辰; for 23:00–24:00 this page keeps the current day’s day pillar (晚子时, the common modern convention). Some schools start the next day at 23:00.
Sky in this shichen
Moving in this shichen
Highlighted: the Moon, the Ascendant and Midheaven (they move fastest), and any body that changes sign or house, or comes within 1° of an exact aspect to your natal chart, during this two-hour window.
Events in this shichen
Planetary stations today
Natal chart
Four Pillars (BaZi)
Five elements
10-year luck pillars (大运)
Birth data and method
Tropical zodiac; geocentric apparent positions (astronomy-engine, checked against Swiss Ephemeris); Placidus houses, Whole Sign when the latitude is too high for Placidus; no houses or angles when the birth time is unknown. BaZi pillars from lunar-javascript with exact solar terms in Beijing time.
Privacy: your birth details are stored only in your account on our server, are used only to draw this page for you, and are never shown publicly. You can change or delete them at any time under Saved birth details.