A Davison chart is a real chart cast for a real moment. You take the midpoint in time between two birth moments and the midpoint in space between two birthplaces, and you cast an ordinary chart for that date, that time and those coordinates.
That is the whole method, and it produces something a composite chart cannot. A composite is a set of midpoints between planetary positions, so it corresponds to no sky that ever existed. A Davison corresponds to an actual configuration of the actual sky, at an actual place on the ground. Every planet in it was really there. Because of that it behaves like a natal chart under every predictive technique: it can be progressed, transited, and given a solar return without any special construction.
One thing to say before anything else. The interpretive literature on the Davison chart is much thinner than the literature on the composite. Robert Hand's Planets in Composite runs 191 pages and carries several hundred delineations for the composite. There is no equivalent volume for the Davison. What exists is a method, a small amount of practitioner commentary, and a great deal of repetition of the same few paragraphs. This page will not invent the difference.
How A Davison Chart Is Calculated
Three steps.
- Find the midpoint in time. Convert both birth moments to a single standard, usually Universal Time, and find the instant exactly halfway between them. In practice this is done by averaging the two Julian day numbers.
- Find the midpoint in space. Average the two latitudes and the two longitudes to get a set of coordinates.
- Cast the chart. Erect an ordinary chart for that moment at those coordinates, exactly as if somebody had been born then and there.
If two people were born ten years apart, the Davison date falls roughly five years after the older birth. If one was born in Oklahoma and the other in California, the Davison place is somewhere in between, and often somewhere neither of them has ever been.
| Composite | Davison | |
|---|---|---|
| What is averaged | Each pair of matching planetary positions | The two birth moments and the two birthplaces |
| Result | A wheel of midpoints | A chart for one real moment |
| Corresponds to a real sky | No | Yes |
| Houses | Derived from the composite Midheaven at the latitude of residence | Ordinary houses for the midpoint place |
| Progressions and returns | Possible only by a special construction | Run exactly as on a natal chart |
| Depth of published doctrine | Substantial | Thin |
Where The Technique Came From
Ronald C. Davison, 1914 to 1985, was an English astrologer, president of the Astrological Lodge of the Theosophical Society in London and editor of The Astrology Magazine. He introduced the time and space midpoint chart in his 1977 book Synastry: Understanding Human Relations Through Astrology, published by Weiser.
The chronology is worth having straight, because it explains the imbalance in the literature. John Townley introduced the space midpoint composite around 1972 and 1973. Robert Hand's Planets in Composite followed in 1975. Davison's time midpoint chart arrived in 1977, into a decade already crowded with relationship chart constructions, and Townley, who was there, describes it as coming late in Davison's working life rather than sitting at the centre of it.
The Awkward Part Of The Method, Stated Plainly
Two features of the technique are genuinely odd and are usually skipped over.
The moment often predates one of the people. If there is a wide age gap, the Davison chart is dated to a time when the younger partner had not been born. The relationship's chart is set before one of its participants exists.
The place is usually nowhere. Averaging two sets of coordinates lands you at an arbitrary point. It is frequently in open water, and it is very often somewhere neither person has been. Townley works the example of two well documented film actors and finds the midpoint on a mountain slope in New Mexico that neither of them has likely heard of.
Neither of those is a fatal objection. The prenatal epoch, the solar return relocated to a place you have never lived, and the horary chart cast for the astrologer's location rather than the querent's all have the same shape of problem, and all remain in use. But they are the reason the Davison has never displaced the composite, and it is more useful to say so than to pretend the construction is self evidently sound.
Note also who is making the criticism. Townley is the person who introduced the composite. He is not a neutral party in this comparison, and his verdict that the Davison lacks a compelling rationale or track record should be read as a partisan one from someone who was present for the whole argument.
Corrected And Uncorrected Davison Charts
There is a small technical wrinkle that shows up in software and confuses people.
The Midheaven computed for the exact time midpoint does not quite match the composite Midheaven, which is the midpoint of the two natal Midheavens. The discrepancy is usually less than a degree. Some implementations offer a corrected Davison, in which the time is nudged so that the Davison Midheaven falls exactly on the composite Midheaven, and an uncorrected Davison, which uses the strict time midpoint and accepts the small difference.
Astrodienst offers both and labels them. The difference is small enough that it will not change a reading, but if you are comparing a chart across two pieces of software and the angles disagree by a fraction of a degree, this is usually why.
What The Davison Is Used For In Practice
The consistent claim across practitioner sources is that the composite describes the relationship as it presents and as others perceive it, while the Davison describes the relationship as it is experienced from inside. That distinction is widely repeated and it is not sourced to a controlled comparison anywhere we can find. Treat it as working practice rather than doctrine.
The one claim that follows from the method itself, rather than from anybody's opinion, is the predictive one. Because the chart is a real moment, transits to it, secondary progressions of it, solar arc directions from it and solar returns for it are all ordinary operations. That is the Davison's real distinguishing feature and it is covered in how to read a Davison chart.
How Thin Is Thin
Being specific about the gap, since it governs how much weight this chart should carry in a reading.
- Davison's own book is not in our library. Everything on this page about his method comes from secondary description rather than from his text, and it is marked as such.
- Hand never mentions the Davison chart. Not by that name, not as a time and space midpoint chart, not anywhere in 191 pages, and not in his index. He presents the midpoint composite as the technique and does not compare it with any rival construction.
- There is no Davison equivalent of Hand's delineation corpus. No canonical set of Davison planet in house or planet to planet readings by a single author working from case material.
- What circulates instead is the method plus general natal delineation applied to it.
That is not an argument against using the chart. It is an argument for reading it with natal technique you already trust, rather than looking for a Davison specific doctrine that has not been written.
Frequently Asked Questions
What Is A Davison Chart In Simple Terms?
A birth chart for a relationship, cast for the date, time and place exactly halfway between the two people's births. Unlike a composite, it is a moment that really happened.
Is The Davison Chart Better Than The Composite?
They do different jobs and neither has been shown to outperform the other. The composite has far more published interpretive material behind it. The Davison has the advantage that it is a real moment, which makes progressions, transits and returns straightforward.
Why Is My Davison Chart In The Middle Of The Ocean?
Because the method averages two sets of coordinates, and the average of two places on land is often water. This is a known feature of the technique rather than an error in your data.
Can The Davison Date Be Before One Person Was Born?
Yes, and it commonly is when the age gap is wide. The midpoint in time between a 1963 birth and a 1975 birth falls in 1969, when one of the two people did not yet exist.
Who Invented The Davison Chart?
Ronald C. Davison, an English astrologer who led the Astrological Lodge of the Theosophical Society in London, in his 1977 book Synastry: Understanding Human Relations Through Astrology.
What Is The Difference Between A Corrected And An Uncorrected Davison Chart?
An uncorrected Davison uses the strict midpoint in time. A corrected one shifts the time slightly so that the resulting Midheaven lands exactly on the composite Midheaven. The gap between them is usually under a degree.
Recommended Reading
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- John Townley, "Composites Vs. Davison Time Charts," astrococktail.com, for the dates of Davison's life, his role at the Astrological Lodge of the Theosophical Society, the 1977 publication of Synastry: Understanding Human Relations Through Astrology, the chronology against the space midpoint composite, and the worked example of a midpoint place. Townley introduced the composite and his assessment of the Davison is a partisan one.
- Ronald C. Davison, Synastry: Understanding Human Relations Through Astrology (Weiser, 1977), cited for the origin of the technique. Not held in this library and not read for this page.
- Astrodienst, chart type documentation, for the corrected and uncorrected Davison distinction and the sub degree Midheaven discrepancy.
- Robert Hand, Planets in Composite: Analyzing Human Relationships (Para Research, 1975), cited here for a negative result: the Davison chart is not mentioned anywhere in the book or its index.
Continue Learning
Next: How to Read a Davison Chart and Synastry vs. Composite vs. Davison. See also What Is a Composite Chart, How to Read a Composite Chart, What Is Synastry in Astrology and Capacity for Relationship in a Birth Chart.