Astronomical horology

Your sky,
engineered.

An astronomical clock calibrated to the minute of your birth. Your natal chart is set into the dial; the present sky turns around it in real time.

< 0.6′Planetary accuracy
2Calibres in production
0 bytesBirth data stored
The Zodial Tourbillon showing the live sky
LIVE · YOUR SKY--:--LST --
MOON--Sky mode · no birth data
The Movements

Five calibres.
One sky.

Each calibre is a working instrument. All five run on one astronomical engine, so the Sun hand, the rising degree and the lunar phase agree with each other and with the sky outside.

Tourbillon movement: natal wheel with a rotating tourbillon cage, sky ring and 24-hour ring
CALIBRE Z-01Available

Tourbillon

The natal wheel sits at the centre, oriented to your Ascendant with unequal Placidus houses. The sky ring turns with local sidereal time. The tourbillon cage completes one revolution per sidereal day, its needle indexed to 0° Aries.

24 hUnequal-hour ring
1 HzBalance beat
27Nakshatra band
Orloj movement: astrolabe dial with sky bands above a calendar plate
CALIBRE Z-02Available

Orloj

An astrolabe after the Prague Orloj of 1410. A stereographic sky plate with civil, nautical and astronomical twilight for your latitude; Old Czech and Babylonian hours; an eccentric zodiac ring; and a calendar plate carrying your daśā periods and progressions.

3Hour systems
−18°Twilight to night
365Day calendar plate
Antikythera movement: Egyptian calendar and zodiac rings with planet pointers above the Metonic and Saros spirals
CALIBRE Z-03Available

Antikythera

A working reconstruction of the mechanism raised off Antikythera in 1901. The front carries the Egyptian civil calendar set to the true Nabonassar date, the zodiac, and pointers for the Sun, the half-silvered Moon and the five classical planets, with pin-and-slot gearing for the lunar anomaly. The back carries the Metonic spiral with Olympiad and Callippic dials, and the Saros spiral marked with the eclipses of the current cycle.

235Metonic lunations
223Saros lunations
365Egyptian days
Orrery movement: planets on brass arms around the Sun, inside the geocentric transit track and zodiac
CALIBRE Z-04Available

Orrery

A heliocentric planetarium. Every planet rides its arm at its true heliocentric longitude, on an orbit traced from a full revolution of real positions and lit from the Sun; the Moon circles the Earth. Around it, the transit track gives the geocentric longitudes astrology reads, with retrograde flags, and a sky rose at the Earth shows where each planet stands in our sky.

10Bodies on arms
2Frames of reference
℞Retrograde flags
Lunar Mansion movement: Chinese xiu, Arabic manazil and Vedic nakshatra rings around the Moon as seen from the observer
CALIBRE Z-05Available

Lunar Mansion

One Moon hand reads three traditions of lunar mansions at once: the 28 Chinese xiu, bounded by their determinative stars of date; the 28 Arabic manazil; and the 27 nakshatras with their padas. A tithi ring turns with the Sun hand, so the Moon hand reads the lunar day. At the centre, the Moon as it stands in your sky, its bright limb turned to your zenith and its maria placed with the current libration.

28Xiu and manazil
27Nakshatras
30Tithis

Complications

Every function
earns its place.

In horology, a complication is any function beyond hours and minutes. Ours are astronomical and astrological, each computed from your chart and the present sky, each fitted or removed like a module on a movement.

Natal Wheel

Your chart at its true Ascendant, with Placidus, Porphyry or Whole Sign houses, and every body at its exact degree.

Module 01Natal

Aspect Lattice

Natal aspects drawn as a lattice, with adjustable orbs. Applying and separating aspects are rendered distinctly.

Module 02Natal

Live Transits

The present sky over your chart. A line brightens as a transiting planet closes on exact aspect to a natal point.

Module 03Natal

Sidereal Sky Ring

The sky above your location: the rising degree, the Midheaven, day and night arcs, and the Moon at its true phase.

Module 04Sky

Planetary Hours

Twenty-four unequal hours set by local sunrise and sunset, ruled in Chaldean order. The current hour is lit.

Module 05Sky

Nakshatra Band

The twenty-seven lunar mansions, with the Moon's current nakshatra, its pada, and when it changes.

Module 06Vedic

Tithi & Phase

The lunar day, from Shukla Pratipada to Amavasya, beside a Moon rendered at its exact illuminated fraction.

Module 07Vedic

Void of Course

An arc that opens at the Moon's last major aspect in a sign and closes at its ingress, timed to the minute.

Module 08Sky

Vimshottari Daśā

Your planetary periods as a sub-dial, from mahādaśā to antardaśā, the hand on the current period.

Module 09Vedic

Progressions

The secondary progressed Sun and Moon: one day of motion for each year of life.

Module 10Natal

True Analemma

The Sun on its true figure-eight, from the equation of time and declination, with your birthday marked.

Module 11Natal

Sidereal Tourbillon

A cage turning once per sidereal day at the centre of the dial. It is a working sky hand, indexed to 0° Aries.

Module 12Sky

Day Ruler

The ruler of the day and of the hour, for timing a launch, a letter or a meeting by the classical method.

Module 13Sky

Fixed Stars

Forty bright stars from the Yale Bright Star Catalogue, precessed to date, with conjunctions and parans to your chart.

Module 14Natal

Thermodynamic Lens

An optional daily card that reads the sky through the four laws: one action, one lens, one trap, one experiment.

Module 15Daily

Hermes

An astrologer that reads the complications above and states what your clock is showing, with the data it used.

GuideObservatory
Swipe to see all 16 modules →
How it works

Commissioned in four movements.

Choose a calibre

Tourbillon, Orloj, Antikythera, Orrery or Lunar Mansion. Switch at any time; your chart moves with you.

Z-01 Tourbillon · selected

Enter your moment

Date, time and place of birth. Without a time, we cast a noon chart and leave out everything that depends on it.

12 Apr 1988 · 06:40 · Edinburgh

Set complications

Fit modules on a live preview. Each change is computed on your device as you make it.

Transits on · Daśā on · Labels off

Keep it running

Download it as a single file that runs offline, or export a poster or a day-long time-lapse.

tourbillon.html · offline

BlairPartner
RosaMother
KaiCofounder
YouAlex
☉ △ ♀ · 0°11′ ♂ ☌ ♄ · 0°48′ ☽ ☌ ♂ · 0°45′
Constellation

Every bond,
side by side.

A chart for each person who matters: a partner, a parent, a cofounder. The engine reads every aspect between their chart and yours, with each planet's house and rulerships in its own chart.

  • ☍
    Layered synastryEvery aspect between two charts, ranked by weight, with the houses each planet rules and where it lands in the other chart.
  • ⊗
    Composite and Davison chartsThe relationship as its own chart, by midpoints or by the midpoint in time and place.
  • ✦
    Shared transitsThe slow-planet transits that touch both charts at once, with their windows and exact dates.
Open the Constellation →Up to 6 charts · free

◈ Add a chart only with that person's consent. Charts stay in your browser and are deleted in one tap.


Hermes · Observatory

It reads
your actual dial.

Horoscope bots recite sun-sign copy. Hermes reads the complications on your dial (your transits, the hour ruler, the Moon's void) and answers from them, citing degree, orb and time.

  • ☊
    Grounded in your chartEach answer names the transit, orb and timing behind it.
  • ☽
    Conditions, not verdictsIt sets out what is in your favour and what to manage, and identifies windows such as after the void or in a Venus hour. The decision stays yours.
  • ✦
    Prepare for what's aheadA look 30 to 90 days forward, with the actions that suit the current window.
Join the waitlist →Opening with the Observatory
☿
HermesReading Aurelia's Tourbillon · Austin · Sat 10 Oct
Why is it so hard to focus today?
The transiting Sun at 16°45′ Libra is 25′ from a square to your Neptune at 17°10′ Capricorn, applying, exact tomorrow morning. Sun square Neptune dissolves outlines: strong for drafting and design, weak for figures and fine print.

It is also Amavasya, the dark-moon tithi, traditionally kept for rest and completion. Draft today. Edit on Sunday.
☉ □ ♆ · 0°25′ applyingTithi · Krishna 15
When should I send the proposal?
Not during the void, which runs from 6:07 PM today to 10:21 AM Sunday. After the Moon enters Scorpio, take the next Mercury hour: Sunday, 4:10 PM. Scorpio Moon rewards a proposal that is direct and specific about terms. Your hours ring marks the window in cyan.
VOC ends · Sun 10:21 AMHour of ☿ · Sun 4:10 PM

Access

Begin with the sky.
Make it yours.

Studio

All five movements, every complication, your chart.

$0
Free, no account
  • All five movements, live
  • Natal wheel, transits, daśā, nakshatras, progressions and more
  • Offline HTML clock, PNG poster and day time-lapse
  • Constellation: up to 6 charts with synastry, composite and shared transits
  • Share links that keep your settings
Create your clock
Waitlist openObservatory

Hermes, the daily digest and your sky in your pocket.

Founding
membership
Rates announced to the waitlist first
  • Hermes, with the transit, orb and timing behind every answer
  • Daily digest and Hermes by WhatsApp, SMS or email
  • Prepare for what's ahead: 30 to 90 days forward
  • Transit, return and daśā alerts
  • Readings with audio
  • New movements as they're released
Join the waitlist
Atelier

Objects and commissions, made to order.

By request
Gifts, prints and licensing
  • A clock for a birth, a wedding or a launch
  • Archival giclée prints, framed
  • Bespoke movements for brands and studios
  • Licensing for physical dials
Enquire
Zodial

The sky has kept time
since you arrived.

Now you can watch it.

Create your clock →