About
AstroClock is a real-time, privacy-first astrology platform that computes everything locally in your browser using Swiss Ephemeris compiled to WebAssembly (WASM). You get scientifically‑grounded planetary positions, precise transits, strengths, retrogrades, and aspects — all in a fast interface that keeps working offline after the first load.
Mission
Our mission is to unite astronomical precision with readable symbolism. We believe interpretable analytics, transparent methods, and user sovereignty (your data stays with you) make astrology more useful, respectful, and empowering.
How AstroClock works
AstroClock embeds the Swiss Ephemeris (the same astronomical library used by professional astrology software) and compiles it to WebAssembly. WASM lets your browser run high‑precision code at near‑native speed. No server calls are required for ephemeris math, so the app keeps working offline once the engine is cached.
- Real‑time computation: positions update continuously; not precomputed tables.
- Offline capability: after first load, Swiss Ephemeris and data files are stored in your browser’s cache/service worker.
- Local fallback: if Swiss can’t load (e.g., first visit with no internet), AstroClock still functions in Local mode.
Want the technical deep‑dive? See Swiss Ephemeris — Accuracy & Why It Matters.
What makes it different
- Swiss‑grade accuracy: high‑precision calculations for fast points, retrogrades, and exact entry/exit moments.
- Full transparency: aspect badges show symbol, orb, and direction (↑ applying / ↓ separating) for immediate context.
- Interpretation with structure: strengths/weaknesses, retrograde notes, Transit→Natal “why” explanations.
- Resilient design: works smoothly even with spotty connectivity; charts compute locally.
- Privacy by design: no account required; inputs stay in your browser.
Explore the interface on the Features page, or read FAQ for quick answers.
Zodiac & house systems
AstroClock supports multiple frames so you can compare interpretations:
- Zodiac systems: Tropical, Sidereal (Lahiri/KP), True Sidereal — MTZ
- Compare frames: Tropical vs Sidereal (decision guide)
- Methodology: True Sidereal (MTZ midpoint) (constellation‑aware boundaries incl. Ophiuchus)
- House systems: Whole Sign, Equal (from Asc degree), and (with Swiss) Placidus
Privacy & data
- Local‑first: your birth data and settings are stored in your browser (
localStorage); not uploaded to our servers. - Offline place lookup: when offline, enter coordinates as
lat,lon(e.g.,40.713,-74.006); name lookup requires internet. - Ephemeris caching: the WASM engine and data files are cached after first use; they only re‑download if you clear storage.
For specifics and tips, see FAQ → Basics & Offline.
Accessibility & performance
- Readable defaults: high‑contrast palette and scalable fonts by system preferences.
- Keyboard support: tab order and focus outlines for controls; details/summary for structured sections.
- Fast LCP: optimized assets and caching reduce first‑paint delays on repeat visits.
- Low‑latency updates: WASM keeps interactions responsive for date/time simulations.
Roadmap
- Sync‑safe sharing (export/import chart settings without storing personal data on a server).
- Extended aspect patterns and optional minor aspects.
- Additional house systems and sidereal standards.
- In‑app glossary and context tips for beginners.
Have a suggestion? We’d love to hear it.