How Synastry calculates and explains your chart

Your chart starts with the information you provide

Synastry uses your birth date, time and birthplace to calculate the sky for that moment. The birth time matters because the Ascendant and houses change throughout the day. A chart can only be as dependable as the information behind it.

The public no-account calculator uses Astronomy Engine planetary positions with Synastry’s local house, lunar-node and lunar-apogee calculations. The account chart service uses Swiss Ephemeris. The displayed calculation source and settings identify the result; different engines and conventions can produce small differences, especially near a boundary.

Public astrocartography uses Astronomy Engine equatorial positions and sidereal time at the supplied birth instant to plot rising, setting, upper-meridian and lower-meridian lines. Account maps identify their Swiss Ephemeris source. Both use geographic coordinates; lines depend on an accurate birth time and are symbolic interpretation tools, not travel or relocation predictions.

Optional paran lines mark latitudes where two planets simultaneously occupy angular positions in the calculated birth-sky snapshot. The map extends those crossing latitudes around the globe and identifies the planet pair and angles. This is a frozen natal-position method, not a search over a full day of changing planetary positions. Paran proximity uses a separate one-degree latitude band; it is not the distance to a planet’s ordinary angular line.

Astronomical coordinates provide the chart’s structure. The interpretations describe symbolic traditions for education and personal reflection; they are not scientific assessments of personality or promises about your future.

Current transits and your horoscope

The free transit calculator compares the current sky with the recorded birth chart. Each reading names a calculated transiting-to-natal contact, its aspect and orb. The visible calculation time identifies the sky being shown. The page refreshes while it is open and visible, and you can request a fresh calculation.

The horoscope draws concise reflections from those actual contacts and our transit interpretation library. It is not a prediction of events. Natal placements and current transits remain distinct; an older result keeps its timestamp if a refresh cannot be completed.

Western and Vedic charts use different reference systems

Your Western chart uses the tropical zodiac. The public celebrity charts with a supported birth time use Placidus houses. Personal chart settings are displayed with the chart so you can see which house system was used.

The Vedic view uses the sidereal zodiac with Lahiri ayanamsha, mean Rahu and Ketu, and Whole Sign houses. It shows rashis, nakshatras and padas from those positions. Classical drishti uses its own whole-sign relationships; it is different from the Western aspect lines. Uranus, Neptune and Pluto are presented as modern additions rather than classical grahas with traditional rulerships.

These are specific conventions, and another calculator can choose different ones. Compare the displayed settings before interpreting a difference as an error. The Vedic guidebook also explains traditions and techniques that are not all calculated on the website.

What an unknown birth time changes

Many public figures have a well-sourced birth date without a dependable public birth time. Synastry labels those profiles clearly. Their planetary ranges are sampled across the birth date and possible time zones; they are not a chart for an assumed noon birth.

A range may cross a sign, lunar-phase or nakshatra boundary. When it does, the profile shows the alternatives. Rising signs, houses and quadrants remain unavailable without a supported time. The displayed ranges come from discrete samples, so positions between samples may extend beyond the shown bounds.

A reported time is not automatically a birth-certificate time. Where a source is available, the profile explains whether the time comes from a historical record, an official announcement or a family recollection. The source and its limitations remain visible beside the chart.

Moon phase, Lilith and aspects

Your birth-Moon phase comes from the directed separation of the natal Sun and Moon. Synastry uses eight phase bands and shows the phase for the birth moment when that moment is known. A date-only profile may have more than one possible phase.

The optional Lilith point is Mean Black Moon Lilith, the mean lunar apogee. It is different from asteroid Lilith and the osculating point often called True Lilith. Major and minor aspects use their displayed angle and orb rules. Pattern highlights identify chart geometry; they do not establish that a particular life event will happen.

Two numerology systems, transparent name choices

The numerology view presents Pythagorean and Chaldean calculations separately. A birth-date calculation and a name calculation answer different questions within those traditions. The spelling used for the name is shown so you can understand the result.

A celebrity profile uses a supported documented birth-name spelling where one is available; otherwise it identifies the catalog name as its basis. The profile does not silently turn an unverified display name into a verified full birth name. Name readings can change with a different spelling, and some scripts are not supported by the current transliteration rules. Chaldean compound meanings cover the traditional 10–99 catalog alongside root-number readings.

Tarot draws and birth cards

The public tarot reading uses Synastry’s custom 78-card deck. Your browser randomly draws one card or three distinct cards for Situation, Tension and Next step. Reversed cards are optional. A draw is not selected from your birth information or inferred circumstances; its meaning is a prompt for reflection rather than a prediction.

The numerology birth-card section uses the Tarot School’s four-part date convention: month plus day plus the first two and last two digits of the birth year, followed by the displayed reductions. In this convention, 19 produces the three-card sequence 19, 10 and 1; 22 reduces to 4 and belongs to the 13/4 pair. The Fool is numbered 0 and is not a birth card in this method. Other tarot traditions use different methods.

Birth cards are an additional symbolic lens. They do not replace the Pythagorean or Chaldean calculations, and matching cards do not establish a shared personality or relationship outcome. Synastry’s card explanations and reflection prompts are original editorial text.

Sources, photographs and corrections

Public profiles link to their birth-information sources. Licensed photographs include a source and credit where an image is available. A missing photograph or birth time stays missing until supported material can be added.

The public-figure catalog is imported from Wikidata’s published CC0 data. Historical birth times come from the Open Gauquelin Database under CC BY-SA 4.0, credited to Open Gauquelin Database, Thierry Graff and the original collectors, and individually reviewed records link their primary sources. Birth dates, times and places are factual public information; Synastry publishes each record with its source and evidence level and does not reproduce other sites’ horoscope interpretations or artwork.

If you notice an incorrect date, time, place, name or photo credit, contact support@synastry.my with the profile link and a public source that supports the correction. Please do not send private identity documents. For requests about your own personal information, use the current privacy notice and grayson@sableon.io.

Place search and geographic sources

Birthplace and astrocartography city search use a locally hosted adaptation of the GeoNames cities500, countryInfo and admin1CodesASCII exports retrieved September 8, 2026. This snapshot contains 235,694 places across 246 country and territory codes. It covers populated places above 500 inhabitants or administrative seats; it is not a complete list of every hamlet, neighborhood or birth facility.

Data credit: GeoNames, CC BY 4.0. We select location and time-zone fields, join country and administrative labels, normalize names and aliases, and divide the index into bounded search files. Coordinates describe city centres, not a hospital or street address. Contemporary place and administrative names can differ from historical records. The calculator checks the recorded time zone separately.

Upstream notices: Contains Ordnance Survey data © Crown copyright and database right 2010. Contains public sector information licensed under the Open Government Licence v1.0. Geographic data is provided as-is; selecting a place does not independently verify its historical time-zone boundaries.