The sky is calculated locally.

Our sky explorer and lunar calendar use Astronomy Engine 2.1.19 by Don Cross, an open-source astronomical calculation library distributed under the MIT license. A copy is served from this website. Calculations happen in your browser, with no API key, account, payment, or external calculation service.

Planetary longitudes are geocentric: they describe the direction of a body as viewed from Earth’s center. The planetary calculation uses light-time correction and aberration through Astronomy Engine’s GeoVector and converts to the true ecliptic of date with Ecliptic. The Moon uses EclipticGeoMoon. We present the longitude as a tropical zodiac sign plus degrees within that sign.

The tool accepts dates from 1800 through 2100. The current sky uses your device clock at page load. A wrong device clock will produce a wrong current chart. Displayed degrees are rounded down to the nearest arcminute; this display precision is not a guarantee of observational accuracy.

Retrograde labels come from the signed change in ecliptic longitude between 12 hours before and 12 hours after the selected moment. This gives an average apparent daily motion. Very close to a station, a more specialized ephemeris may classify the exact turning moment differently.

The conventions are visible.

We use the tropical zodiac: twelve equal 30° divisions of ecliptic longitude, starting from the March equinox. These signs are not the irregular astronomical constellations. We do not offer a sidereal mode or silently change the coordinate system. Different astrological schools use different systems for different reasons.

The aspect calculator searches five major angular relationships. Conjunction and opposition allow an orb of 8°, square and trine 6°, and sextile 4°. The wheel only draws aspects within 3° to keep it legible. Orbs are interpretive conventions; they are not physical thresholds in nature. We report separation from the exact aspect, not a compatibility or likelihood score.

Moon illumination is the fraction of the visible disk illuminated by sunlight. Broad phase names are assigned to eight sectors around the lunar phase angle. The calendar separately searches the precise instants of the new moon, first quarter, full moon, and last quarter. Calendar times appear in your device’s timezone and UTC. The diagram is a stylized illustration rather than a realistic view from your location.

A planetary chart has limits.

The chart explorer calculates planets in signs and major aspects. It does not calculate houses, the ascendant, the midheaven, lunar nodes, asteroids, Arabic parts, or a complete natal interpretation. We leave these out rather than invent them from missing birth information.

Enter the historical UTC offset for the birthplace and date, including any daylight saving adjustment. Current timezone offsets can differ from historical ones. If the time is unknown, our noon option is an estimate. The Moon can move noticeably across the day and may change sign. Close aspects can also change. Always label a noon chart as an estimate.

For precise timing near sign boundaries or stations, or for professional historical research, compare results against a specialist ephemeris and verify the time conversion. This site is designed for learning and exploration, not navigation or observational planning.

Interpretation is not measurement.

Our original reference guides describe common modern Western astrological language alongside introductions to other traditions. Interpretive claims are framed as symbolic conventions. They are not evidence that the sky determines personality, relationships, health, or future events.

Astrology and astronomy share a history but are distinct practices today. Astronomy uses mathematical models and observations to describe celestial objects. Astrology assigns symbolic significance to celestial patterns. A precise planetary calculation does not validate an astrological prediction.

Our daily horoscope page displays a saved FreeHoroscopeAPI reading when you request one, with the provider’s original publication date. Our server refreshes these readings in the background, allows slow responses more time and retries failures with increasing delays. Supplier-requested waiting periods are respected. The last valid reading remains available with its date during an outage; no substitute prediction is invented. Browser update checks pause when the page is hidden or offline, while server retries continue. Our sister site, Horoscope.mobi, adds weekly and monthly readings and deeper reflective tools. Astrology.mobi’s sky tools do not consume those readings or turn them into numerical scores.

Your chart stays with you.

The chart form processes your entries in the browser. It does not submit birth data, add it to the URL, create an account, or save it to local storage. Printing or saving a PDF uses your browser’s own print feature.

This site does not load analytics, advertising scripts, external fonts, or third-party calculation widgets. The optional daily horoscope page contacts this site’s own reading service. Our server sends the selected zodiac sign and reading period to FreeHoroscopeAPI; it does not forward your IP address, birth date or birth time. Private, size-limited service logs record request timing, HTTP status, retry decisions and recovery, so persistent outages can be diagnosed. These service logs do not include visitors’ IP addresses, birth information or reading bodies. The hosting server may retain ordinary access logs such as requested paths, timestamps, and IP addresses. External reference links and Horoscope.mobi have their own privacy practices.

Sources and licenses.

Editorial and calculation methods last reviewed October 28, 2026.