Horary Astrology Chart Calculator

Take an example question, about whether a business partnership will go ahead (a 7th house matter), cast for 3:42 pm on Thursday, 29 October 2026, in Denver, Colorado (21:42 UTC). Pisces rises at 11° 04’, so Jupiter, ruler of Pisces, is the significator for the querent. Virgo is on the 7th cusp, so Mercury, ruler of Virgo, is the significator for the matter, while the Moon serves as the querent’s co-significator.

Jupiter at 24° 04’ Leo is peregrine by the tables this calculator uses: the degree falls in Mars’s Egyptian bound, and in a day chart the Sun rules the fire triplicity.[2] Lilly’s Ptolemaic terms give 19° to 25° Leo to Jupiter, so by his tables Jupiter would hold its own term here and would not count as peregrine.[2] Mercury at 18° 42’ Scorpio is retrograde, in its own Egyptian bounds, and under the beams, about 12 degrees from the Sun (within the 17 degrees Lilly gives for being under the beams).[2] Mercury was applying to a square with Jupiter, then turned retrograde at 20° 59’ Scorpio on October 24, about 2.4 degrees short of the square point, which stood at 23° 21’ Scorpio that day. Jupiter has moved on since, and at the moment of the chart Mercury stands 5.4 degrees from the square point at 24° 04’ Scorpio, moving away from it. Lilly calls this refranation: the applying planet turns retrograde before the aspect completes.[16][2] So no applying aspect joins the two rulers, and there is no reception between them; separating significators cannot perfect without help from another planet.[2] The Moon has just separated from a sextile to Jupiter and applies to a trine with Venus at 27° Libra, a hundredth of a degree from exact, before she leaves Gemini.

Two considerations before judgment flag in both house systems. First, the Moon sits at 27° 20’ Gemini. Abu Ma’shar counts the end of a sign among the Moon’s corruptions,[9] and the last degrees of most signs fall in the bounds of Mars or Saturn (the end of Gemini belongs to Saturn). The sources fix no exact degree, so 27° is the threshold this calculator uses. Second, the hour belongs to the Sun, which does not agree with Jupiter, ruler of the Ascendant, by rulership, triplicity or nature. Lilly made that agreement his test of a radical chart;[16][2] Bonatti held a chart without it not radical, while Dunn judges such charts anyway.[2]

Switching house systems shifts the placement of two planets. By whole sign, retrograde Saturn at 9° 25’ Aries falls in the 2nd house because Aries is the second sign from Pisces. In Regiomontanus, the 2nd cusp falls at 28° 54’ Aries, which puts Saturn inside the 1st house. That flags a third consideration: Saturn in the 1st, which Lilly counted against the matter, especially when retrograde.[2] Mercury also moves from the 9th house in whole sign to the 8th in Regiomontanus, though it still rules the 7th in both. The calculator stops at these testimonies, and weighing them is your work, or Predict’s.

A horary chart is a chart cast for the moment a question is asked and understood, at the place where it is asked.[2][4] The rising sign and its ruler stand for the person asking, while the house that governs the subject stands for the matter.[2] You read the chart for that one question alone.[2][4]

The person asking is the querent, and the thing asked about is the quesited.[2] The planets that represent them are the significators.[2] The ruler of the Ascendant stands for the querent, and the ruler of the house of the matter stands for the quesited.[2] William Lilly also gave the Moon to the querent as co-significator in every question, and weighed her condition above the Ascendant ruler’s: it is “farre better the Lord of the ascendant be unfortunate than she, for she brings unto us the strength and vertue of all the other Planets”.[2] Because the chart is cast for the question itself, you do not need a birth time or a birth chart.[12] Al-Biruni noted that astrologers read a client’s question “as if it were a nativity” when birth data was unknown.[12]

This calculator casts the chart and lays out the parts a horary reader works through: who stands for what, how the significators connect and receive each other, their condition, and the nine traditional considerations before judgment.

Ask one question you care about, on a matter that has been on your mind for a while.[2] Masha’allah wanted one question at a time, with no second question until the first had been judged, though Barbara Dunn allows several held in mind at the same moment.[2] Bonatti wanted a question that had occupied the asker “for the space of a day and night or longer”, and Lilly warned against judging slight or trivial ones.[2] Horary suits concrete matters: money, property, relationships, work, disputes and lost things.[2][13] Holden notes that theft gets the most space of any question Dorotheus treats, about nine pages in Pingree’s translation.[4] Make your question specific and give it a time frame.[2] Dunn discards open questions such as “Will I ever get married?” in favor of questions with a set period, and does not usually accept questions that reach past two years.[2]

Cast the chart for the moment you understood the question, at the place where you were.[2] Lilly timed charts to the minute he grasped a question; a letter that arrived at three o’clock but sat unopened for hours was cast for the minute he read it.[2] When you ask for yourself, that moment and place are simply now and here, so the form opens on the current time.[2][14] If the question is about something that already happened, the older texts preferred the moment of the event, or when the news reached you.[1][8] When the hour of flight was unknown, Dorotheus and Hephaistion cast a runaway slave’s chart for the hour the master first heard the news.[1][8] Use the past-moment option for that.

Pick the topic, and the tool chooses the house that stands for the matter: the 10th for a job, the 7th for a partner or an opponent, the 2nd for money or a lost object, the 4th for a home, and the 9th for a long journey. Dunn finds questions about your own affairs clearer.[2] For a question about someone else, horary counts derived houses from theirs, so a partner’s money is the 2nd house from the 7th, the 8th.[2]

Ask once.[2] Dunn’s rule is that the same question cannot be asked twice, because a second chart invites a search for a happier answer.[2] When circumstances have changed, a new question is fair.[2]

The tradition allows a question asked on your own behalf, with one dissent. Masha’allah held that “it is not suitable for a sage to look on his own behalf” and wanted the astrologer to ask through another person.[2] Dunn calls that a matter for debate, notes that later authors did not insist on it, and includes several of her own questions in her casebook; Lilly cast a chart for his own stolen fish and got most of them back.[2] When you cast here you are querent and astrologer at once, and Dunn adds that the rule about an afflicted ruler of the 7th, the astrologer’s house, does not apply when the astrologer asks the question.[2]

This is a Western horary chart in the line of the medieval authors and Lilly. KP Prashna belongs to the Krishnamurti system, a separate tradition with its own rules.

Considerations before judgment

Read the considerations first. Lilly calls them the considerations before judgment (Christian Astrology, pages 121 to 123), and he used Bonatti, whose longer list, the 146 Considerations, fills the fifth treatise of the Liber introductorius.[16][2][4] They warn when a question is unripe or when the chart is hard to judge.[2] They are cautions rather than verdicts, and the authorities disagree about how strict to be; Barbara Dunn judges some charts that fail them.[2] This calculator checks nine.

• An Ascendant in its first 3 degrees. Lilly would not judge such a chart unless the querent was very young and described by the rising sign.[2]
• An Ascendant at 27° or later. Lilly made an exception only when the querent’s age in years matched the degree rising, and Ball read a late Ascendant as a sign that the querent had been consulting others about the matter.[2]
• A void of course Moon, by the rule Lilly and Abu Ma’shar used: no applying aspect to a planet before she leaves her sign.[2][6] The Hellenistic definition instead looked thirty degrees ahead regardless of sign.[3] Lilly read a void Moon as matters going hard, yet allowed that she still performs something in Taurus, Cancer, Sagittarius or Pisces.[2]
• The Moon in the Via Combusta, 15° Libra to 15° Scorpio. Al-Biruni explains the stretch by the falls of the Sun and Moon and the dignities of Saturn and Mars in those signs, and Abu Ma’shar marks 19° Libra to 3° Scorpio as its harsher core.[2][9] Ball deferred judgment here; Dunn has not seen enough evidence to treat it as a bar.[2]
• The Moon past 27° of her sign. The sources tie the danger to the last degrees of most signs falling in the bounds of the malefics and fix no degree, so 27° is this calculator’s convention.[9]
• Saturn in the 1st house, which Lilly counted against the matter, especially retrograde. Bonatti held that Saturn in his exaltation there lays aside his malice.[2]
• Saturn in the 7th house. The 7th stands for the astrologer in a horary chart, so an afflicted 7th warns that the judgment itself may err.[5] Dunn sets the warning aside when the question is a 7th house matter, and the calculator does the same.[2]
• A planetary hour that does not agree with the Ascendant by rulership, triplicity or nature. Lilly made the agreement his test of a radical chart; Bonatti held a chart without it not radical, while Dunn judges such charts and finds the agreement in her most fortunate ones.[16][2]
• The Moon within 5° of the South Node. Abu Ma’shar counted the Moon within 12° of either node among her corruptions; the calculator flags only a close conjunction with the South Node, which Lilly scored at minus four.[9][2]

Three of the nine descend from Abu Ma’shar’s eleven corruptions of the Moon: the burnt path, the end of a sign, and the Moon near a node.[9]

The significators and their condition

Then look at the significators and their condition. A planet in its own sign (domicile) or exaltation is strong, whereas one in detriment or fall is weak, and a peregrine planet has no essential dignity at all.[2] Lilly scored these: five points for domicile, four for exaltation, three for triplicity, two for term, and one for face, down to minus four for fall and minus five for detriment or peregrine.[2] A planet joined to the Sun by conjunction in the same sign is combust, which Lilly read as a heavy weakness. Dunn quotes his limit as eight degrees and her glossary allows up to 8° 30’; this calculator uses 8°.[2] He wrote that if the Lord of the Ascendant is combust, neither question propounded will take.[2] Within 17 minutes of the Sun, a planet is cazimi (in the heart of the Sun) and greatly strengthened.[2]

How the significators connect

Next, check the connection and the Moon’s next aspect. Separating significators cannot perfect without help.[2] For applying orbs, Lilly used moieties, which put Saturn and Jupiter within 11 degrees, while Masha’allah largely ignored orbs.[2] Lilly lists perfection by conjunction, sextile or trine “in good places of the Figure”, sometimes by translation or collection of light, “or by the Dwelling in Houses or Dignities”.[2] A square can perfect with difficulty when the planets have dignity or reception.[2] An opposition rarely does; Lilly wrote that he had rarely seen anything brought to perfection that way.[2] Connections can also fail.[2] A third planet can reach a significator first (prohibition), or the applying planet can turn retrograde before the aspect completes (refranation).[2] In frustration, the slower planet joins another planet before the faster one arrives, like Lilly’s two dogs quarreling while a third gets the bone.[2] Which planet does the applying also matters. In Dunn’s reading, when the significator of the thing asked about applies to the querent’s, the matter comes without effort on the querent’s part, and when the querent’s significator applies, the querent makes the move.[2] That is why the results name the planet that applies.

Translation and collection of light

When the significators make no aspect of their own, a third planet can join them. In translation of light, a swifter planet separates from one significator and applies to the other, carrying the nature of the first to the second.[6] Lilly’s stricter form has the significators separating from each other and the translating planet received by the one it leaves.[2] Bonatti reads a perfection by translation as brought about “by ambassadors, friends, or some person interposing himself”.[2] In collection of light, both significators apply to a slower planet, which collects their light.[6] Lilly’s picture is two parties who cannot settle on their own until “a Neighbour or friend accidentally reconciles all differences”; he wanted the collector well dignified and well placed, and Dunn finds perfection by collection fairly unusual in practice.[2]

Reception

Reception tells you whether the planets want each other.[2] A planet in another’s domicile, exaltation, triplicity, term, or face is received by that planet, in that order of strength.[2] Lilly required no aspect for a mutual reception, which can sometimes perfect a matter on its own, and held that a single reception always needs an aspect.[2] Dunn writes that reception usually works through an applying aspect, and that it can matter more than the kind of aspect in bringing a matter about.[2] Masha’allah held that a malefic which receives can still perfect a matter while one that does not receive destroys it.[2]

Timing

When the chart shows a connection, the sources turn its distance into time. John Partridge, whom Dunn quotes, takes the distance between the significators, by body or by aspect, and gives every degree in a fixed sign a year or a month, in a common sign a month or a week, and in a moveable sign a week or a day; angular houses count as moveable, succedent houses as common, and cadent houses as fixed.[2] Gadbury adds that significators above the earth and swift in motion hasten the matter.[2] Bonatti used a different scheme, keyed to the quarter of the chart a significator stands in.[2] Dunn calls timing probably one of the most difficult areas of judgment, and treats a match between the degrees of application and the time scale expected as a confirmation that the chart is radical.[2] The connection card gives the degrees left to go; the conversion is yours.

How a traditional judgment reaches yes or no

Holden traces the core of horary judgment to Sahl’s sixteen configurations of the planets, set out in the ninth century, which include translation of light, prohibition, reception and the void of course Moon.[4] A traditional yes or no comes from weighing these testimonies together.[2] In Dunn’s practice, a single unfortunate testimony, even an unsupported one, can be enough to deny a matter, while a yes takes at least two, and preferably three, strong concurring testimonies.[2] Lilly deferred judgment when the testimonies balanced.[2] This calculator shows each testimony without adding them up. It also leaves out testimonies the sources weigh that it does not compute: besiegement of a significator between two planets, the return of light by a retrograde or combust receiver, a combust ruler of the Ascendant, an afflicted ruler of the 7th, and the Spica exception near 24° Libra inside the Via Combusta.[2]

The calculator casts in whole sign houses by default and offers Regiomontanus as an option. The two systems can put a planet in a different house or give the matter a different ruler.[2][6] Pick one before you start judging and keep to it. Demetra George puts the problem plainly: one house system can answer “Will I find my keys?” with a yes and another with a no.[10]

In whole sign houses, the rising sign is the entire 1st house and each following sign is the next house.[3][6] Because there are no cusps inside the signs and no intercepted signs, the ruler of a house is always the ruler of its sign.[3][6] Brennan treats it as the oldest attested house convention: of the standalone charts in Neugebauer and Van Hoesen’s Greek Horoscopes, about 38 record only the rising sign, 7 give its degree, and 3 give both the Ascendant and Midheaven degrees.[3] Holden and Brennan hold that whole sign was the original system.[3][4] Houlding and Gansten disagree, with Houlding arguing that houses originally divided the whole local sphere and Gansten noting that, to his knowledge, no ancient author actually prescribes whole sign houses.[5][15] We default to whole sign because it was the usual house convention of the Hellenistic period, when Brennan places the first consultation and question charts,[3] and because Predict reads whole sign houses. That way, a free chart here and a Predict judgment agree on which planet sits where.

Regiomontanus divides the celestial equator into twelve 30° arcs and projects them onto the ecliptic through the north and south points of the horizon.[2][13] It carries the name of Johannes Müller of Königsberg in Franconia (1436 to 1476), whose house tables were printed at Augsburg in 1490, though an 11th century description of the method survives.[4][5] Those printed tables replaced the older Alchabitius system as the standard across Europe; Holden’s verdict is that they “looked more scientific”.[4] The cusps in William Lilly’s Christian Astrology (1647) are Regiomontanus; Placidus published his system three years later, and Holden judges that Lilly read it and kept Regiomontanus.[4] Olivia Barclay’s revival advocated Regiomontanus on the strength of Lilly’s example.[4] Lilly’s rules use cusps: his 5 degree rule reads a planet within 5 degrees of the next cusp as acting in that house, and his scoring gives five points to a planet in the Ascendant or Midheaven.[2][5] (This calculator leaves planets in their mathematical houses rather than moving them by the 5 degree rule.)

Switching systems changes specific parts of the reading. A planet in the rising sign but at an earlier degree than the Ascendant, so already above the horizon, sits in the 1st house by whole sign and the 12th by Regiomontanus, so Saturn can fall in the 1st in one chart and the 12th in the other.[6] A Regiomontanus cusp falling in a different sign, or an intercepted sign, can also change the planet that rules the house of the matter.[2] The early and late Ascendant checks stay the same in both. Inside the polar circles quadrant systems can fail, and when Regiomontanus cusps cannot be drawn the calculator falls back to whole sign and tells you.[4]

The word “horary” shortens the 17th century phrase “horary questions”.[3] Chris Brennan divides Hellenistic astrology into three main branches: natal, universal (mundane) and inceptional (katarchic), which reads a venture from the chart of its start. He treats consultation charts, which Dykes calls thought-interpretation, as an application of inceptions that read what was on a client’s mind at the start of a session. Interrogations, charts for a single question, are a fourth branch that emerged later: in his account they began within the Hellenistic tradition and became a full branch only in the medieval period.[3]

The early evidence sits in Hephaistion of Thebes, writing around 415.[1] In Book III of his Apotelesmatika, section III.4 covers knowing a client’s inquiry from the chart of the consultation.[1] Elsewhere in Book III, a chart for a departed wife is cast for the separation “or else at the time that someone inquires from you”, and, when the hour of flight is unknown, a runaway’s chart is cast for when the master heard the news.[1] Historians read this material differently. Brennan reads III.11, 2 as at least one clear reference to question charts in Hellenistic astrology, reversing his own 2007 paper.[3] Benjamin Dykes, editing the same book, accepts that passage as a question chart used as a second-best fallback, yet says Book III yields “a negative answer” for a full-blown horary tradition by the 5th century and calls Persian and Arabic writers its founders.[1] By the late 5th century, a surviving chart that appears to be cast for a question shows the practice in use: a client asked about an overdue ship bound for Smyrna, and its cargo of ostrich feathers, papyrus, cooking implements and medical supplies arrived safe.[3][11]

Persian and Arabic astrologers consolidated interrogations into a full discipline. Masha’allah wrote a book on interrogations containing horary charts from 791 and 794, and Sahl ibn Bishr set out sixteen configurations of the planets that Bonatti and Lilly carried forward.[4] Dykes argues that many of these question texts were rewritten from Dorotheus’s electional rules.[1][7] Latin translators later carried this tradition to Guido Bonatti, whose Liber introductorius devotes its sixth treatise to interrogations.[4]

William Lilly gave the art its most influential English form. His Christian Astrology (London, 1647) runs to almost 900 pages, with its second part serving as a horary treatise built around 35 or more cases from his casebooks. Those casebooks, holding thousands of his horary charts, survive among the Ashmole manuscripts in the Bodleian Library, Oxford.[4] James Holden calls the book “the prime modern sourcebook of horary astrology”.[4] Public interest in astrology declined across Europe from the late 17th century; only in England did almanacs keep it alive at a low level.[4] The modern revival came through Olivia Barclay, whose photocopies of Lilly’s work made the 1985 Regulus reprint possible.[2]