Real positions. Room for uncertainty.
Here is what comes from astronomy, what depends on your birth details, and what is an astrology interpretation.
The positions
We use ephemeris tables from NASA/JPL Horizons for asteroid 3 Juno and planet Venus. Juno here is the asteroid, not the NASA spacecraft with the same name.
The tables contain geocentric apparent ecliptic longitude of date. They account for light travel time, aberration and gravitational deflection. We request observer quantity 31 at Earth's center, with no atmospheric refraction. This is the tropical zodiac, divided into twelve 30-degree signs from the equinox. It is not a sidereal zodiac or a map of the astronomical constellations.
Our static data covers January 1, 1900 through December 31, 2099, with extra samples at both ends. We interpolate four adjacent daily observations using an angle-aware cubic polynomial. The derivative gives the apparent daily motion. We do not estimate Juno's sign from its average orbital period.
We display degrees to two decimal places for a known birth time and an approximate range for an unknown time. Displayed degrees are truncated within the sign so that rounding cannot turn 29.99° into a misleading 30° of that sign. A placement within 0.0001° of a sign boundary is treated as potentially belonging to either adjacent sign. Very slow motion is labeled “Near station” rather than assigned a confident direction.
Your birthplace and local time
The place search uses a local copy of GeoNames cities15000, containing more than 34,000 cities and their coordinates and IANA time zone identifiers. The data is available under CC BY 4.0. You can enter coordinates and a time zone manually if your birthplace is missing.
City matches use approximate city-center coordinates, not a specific hospital or street address. Location accuracy matters for houses. If your birthplace is far from the city center or your house is near a boundary, enter more precise coordinates when available. The 0.05° margin below covers our rising-point approximation, not an inaccurate place or birth record.
Your browser's time zone database converts the local birth time to universal time using the historical rules for that zone, including daylight saving changes. If the clock time occurred twice, you must select the first or second occurrence. If the time never occurred, we ask you to correct it or use unknown time.
Historical time zones are not perfectly documented everywhere. GeoNames assigns the current IANA zone to a place; old political boundary changes may require a different historical zone. For an unusual historical record, check the applicable zone and enter it manually. Use an up-to-date browser because its time zone rules affect the conversion. Before 1962, Horizons uses UT1 rather than modern UTC.
When the birth time is unknown
We check the entire local calendar day. That can be 23 or 25 hours during a daylight saving change, and some historical changes are larger. We include position and motion extrema within the interval, so a brief boundary crossing is not lost.
If Juno or Venus crosses a sign boundary, we show all possible signs and both interpretations. We omit houses. We never substitute a noon birth time and present it as certain.
For a known time, the entered minute represents a one-minute window, centered on that time. If even this short interval leaves more than one possible sign or house, we show the alternatives. If your birth time is only approximate, use the unknown-time mode.
The house system
This version uses whole-sign houses. The zodiac sign containing the ascendant is the first house, and each following sign is the next house. We calculate the eastern intersection of the horizon and ecliptic using your coordinates, sidereal time and obliquity of date.
Whole-sign houses are deliberately simpler to explain than unequal house systems such as Placidus. Their results can differ. We do not switch house systems silently. We check the entered minute and use a conservative 0.05° ascendant boundary margin to cover the approximation in sidereal time and obliquity.
We omit houses at latitudes of 66° or higher, where the rising point can behave unusually. Juno and Venus signs still work. A location without a reliable historical time zone can also limit the calculation.
The progressed Moon calculator
Our progressed Moon calculator uses secondary progressions with an elapsed tropical year of 365.2422 days representing one ephemeris day. We evaluate the selected calendar date at 12:00 UTC. The progressed instant equals the UTC birth instant plus the elapsed time divided by 365.2422. A blank progression date uses the current calendar date in your browser.
For lunar positions we use Astronomy Engine version 2.1.19, with its geocentric lunar longitude in the true ecliptic of date and its Horizons-compatible time conversion. Future leap seconds are held constant for this convention. This is a local calculation using a lunar model, separate from the downloaded Juno and Venus tables. We use a conservative 0.02° calculation tolerance and display either adjacent sign if the position range reaches a boundary.
A known birth time represents a one-minute window. An unknown time spans the full local birth day, which can cover roughly 12 to 15 degrees of lunar movement. Both the natal and progressed Moon can have more than one possible sign. An unknown time can shift sign-change timing by about a year, so we show a month range and omit the next-change estimate if the current sign is uncertain.
We locate the next lunar sign crossing by searching actual calculated longitudes, then convert that ephemeris instant back to a real-life progression date. The estimate includes the birth-time window and lunar calculation tolerance. It is not a forecast of an event. This tool covers input dates from 1900 through 2099 and does not calculate houses, aspects or progressed lunar phases.
The planetary hours calculator
Our planetary hours calculator uses Astronomy Engine 2.1.19 to find the Sun's rise and set for the selected coordinates. Rise and set refer to the Sun's upper limb, including standard atmospheric refraction of 34 arcminutes. We assume sea level and an unobstructed horizon; terrain, elevation and weather are not modeled.
We divide sunrise to sunset into twelve equal elapsed-time intervals, then sunset to the following sunrise into twelve more. The first ruler is the local weekday's planet. Subsequent rulers follow Saturn, Jupiter, Mars, Sun, Venus, Mercury and Moon in a repeating sequence. The day begins at sunrise, so the current planetary day before sunrise is dated the previous calendar day. This follows the traditional planetary hours convention.
The city's IANA time zone handles daylight saving changes. We divide UTC instants before converting each boundary to local clock time, and show dates and UTC offsets to distinguish repeated hours. Displayed times are rounded to the nearest minute. Calendar files retain the calculated boundaries to the second and use UTC, so a calendar app can display them in its own time zone. The current-hour indicator refreshes every 15 seconds while the result is open.
Dates from 1900 through 2099 are supported. If there is no sunrise on the selected local date, no following sunrise within 36 hours, or no sunset between them, we show an unavailable result. We do not extend a planetary day across weeks of polar daylight. Historical time-zone limitations described above also apply. We checked 48 solar events across 16 sample days against Swiss Ephemeris, with a largest difference of about 14 seconds. Swiss Ephemeris is used only to produce offline test references; the website does not load or run it. This sample comparison does not guarantee an error bound for every location and date.
The interpretation
The astronomical placement is a calculation. The relationship meaning is an editorial astrology interpretation. It is not a measured personality trait, a compatibility percentage or a scientifically validated prediction. We do not calculate a soulmate, a marriage date or a relationship outcome.
Our readings focus on commitment, mutual care and questions you can discuss. Juno and Venus offer different interpretive themes, so we show both without turning their relationship into a score.
Privacy and reproducibility
Every calculation loads the same static files and runs in your browser. Your date, time, place and result are not sent to a calculation API or placed in a URL. The source data snapshot and settings are available in our ephemeris manifest; place data attribution is available too.
Read our privacy statement for hosting request details, or calculate your Juno placement.