About Astrojelly and our calculation methods
A playful space for exploring astrology with clear methods and room for your own judgment.
Our cosmic promise
We explain what a tool calculates, label approximations, and keep interpretation separate from astronomy. We do not make promises about destiny, relationship outcomes, health, wealth, or an untested accuracy percentage.
Why we publish these guides
Astrojelly publishes beginner-friendly astrology tools and explanations for people who want to explore their chart without feeling overwhelmed. Our playful jelly illustrations are decorative; the actual calculations use the methods described below.
Our approach to explanations
We separate measurable celestial positions from traditional interpretations. Guides use plain language, show the convention behind a result and link to relevant sources. We welcome corrections when a result or explanation needs more context. Our pages identify the method and its limits so you can understand what a result actually means.
Calculation methods
Planetary positions use the open-source Astronomy Engine library. Western results use apparent geocentric ecliptic longitudes of date. Houses use whole-sign divisions. The ascendant is calculated from local apparent sidereal time and obliquity. The supported birth-date range is 1900–2100, with latitude restricted to below 66° in magnitude for ascendant calculations.
Sidereal exploration uses an approximate Lahiri-like offset of 23.85675° at J2000 plus 0.013968° per year. It is not an exact Lahiri calculation. Nakshatra, pada, Navamsa, and dasha results inherit this approximation and can change near boundaries. Vimshottari periods use 365.2425-day years.
Historical local times are resolved using IANA timezone rules available in your browser. Repeated or nonexistent daylight-saving times require a manual historical UTC offset. Unknown-time charts omit houses and the ascendant and flag possible Moon-sign changes.
Sources and licensing
Astronomy Engine documentation and MIT license describe the astronomical library and its validation. Astrojelly’s interpretations are original introductory explanations of traditional symbolism.
What is not included
This release does not provide certified Swiss Ephemeris Kundli calculations, all divisional charts, Shadbala, Ashtakavarga, full Ashtakoota matching, automated muhurta selection, or professionally reviewed dosha analysis. Those require a separately validated specialist implementation.
Explore the tools ↗Curiosity with clear methods
Astrojelly combines playful design with explicit calculation conventions. Accurate input matters, especially near time, sign and house boundaries. Read the method for the tool you use and distinguish astronomical positions from traditional symbolic interpretations.
Keep exploring your cosmic story
Sample astronomical checks: October 12, 2026
We compared the ten displayed tropical planetary positions for January 1 and June 1, 2000 at 00:00 UT with Astrodienst Swiss Ephemeris tables. Signs agreed in these two cases, and displayed degrees differed by less than 0.02 degrees. London local-time inputs also resolved the winter and summer UTC offsets for those dates.
For October 2026, the monthly lunar calendar matched the U.S. Naval Observatory new Moon, full Moon and last-quarter times to the displayed minute; the first-quarter result differed by one minute. These are sample checks, not certification of every date, rising sign, location, sidereal method or interpretive statement.
Astrodienst 2000 ephemeris tables (mirrored PDF) · U.S. Naval Observatory October 2026 phases