· 9 min read
Return Chart Timing: Solar, Lunar, and Planetary Returns
Solar, lunar, and planetary return charts pivot on one instant. See how planet velocity sets timing precision and how to verify it against JPL Horizons.
T
Torsten Brinkmann
Astrologer & Developer Advocate
Germany49 articles published
Torsten Brinkmann combines 16 years of Western astrology practice with a software engineering background, specializing in astrological calculation tools, birth chart APIs, and planetary aspect analysis. His Computer Science training shapes writing that addresses both the astronomical mathematics behind natal charts and the developer integration patterns for astrology APIs. He is currently writing a technical guide to birth chart calculation for developers.
Computer Science background16 years of practiceWriting a technical astrology guide
Western astrologyBirth chart analysisPlanetary aspectsSynastryForecastTransit forecastingHuman DesignBodygraph analysisAPI integrationAstrology software
Articles by Torsten Brinkmann
· 13 min read
Build a PHP Insight App: Astrology, Vedic, Tarot APIs
Build a PHP astrology, Vedic kundli, and tarot app with the new roxyapi/sdk Composer package. Laravel, Symfony, vanilla PHP, one API key.
· 9 min read
MCP vs Function Calling vs LangChain: AI Agent Guide
Comparing MCP, OpenAI function calling, and LangChain tools for AI agents. Schema, transport, auth, and when to choose each. By RoxyAPI.
· 11 min read
Birth-Time Rectification API: Handling 15 Minute Uncertainty
Sweep the natal endpoint across a plus or minus 15 minute window, separate stable features from collapsing ones, surface confidence by RoxyAPI.
· 11 min read
Whole Sign Fallback at Polar Latitudes for Birth Chart APIs
Placidus and Koch fail above 66 degrees north. Here is what RoxyAPI returns at the cutoff and how to override to Whole Sign for traditional charts.
· 10 min read
Retrograde Station Detection: Stationary Point Edge Cases
Why naive day-step retrograde detection misses planetary stations, and how to detect zero crossings of longitude velocity for the astrology API.
· 15 min read
Timezone Bugs in Astrology: A Complete Developer Guide
Timezone bugs silently corrupt natal charts. DST ambiguity, historical offsets, IANA vs decimal inputs, and how to debug chart mismatches.
· 9 min read
How Biorhythm Energy Ratings Work: The 1-10 Scale Explained
The biorhythm energy rating condenses three primary cycles into a 1-10 score. Learn how the scale works and how to display it.
· 10 min read
VSOP87 vs JPL DE440: Which Planetary Ephemeris to Use
Compare VSOP87 and JPL DE440 planetary ephemeris models for accuracy, speed, and file size. Find out which fits your astrology app or astronomy project.
· 10 min read
Planetary Aspect Calculation for Developers: Orbs and Edge Cases
How to calculate planetary aspects correctly. Covers orb systems, the 360 degree wrap-around bug, applying vs separating detection, and a working API example.
· 12 min read
Placidus House Calculation for Developers: The Math
How Placidus house calculation works, the iterative algorithm behind house cusps, and why it breaks at extreme latitudes. Developer guide with working API example.
· 11 min read
Birth Chart Calculation From Scratch: The Full Algorithm
Every step of a birth chart calculation explained for developers. From UTC conversion to aspect orbs, with a working API example.