Features

AstroClock blends precise astronomy with readable astrology. Compute accurate charts, see strengths/retrogrades at a glance, and view major aspects with orbs and direction — all in real time, even offline.

Core chart calculation

• Natal chart: Sun, Moon, Ascendant, MC, houses, placements.
• Transits: current planetary positions with clear entry/exit timestamps.
• Ephemeris: automatic Local fallback + Swiss Ephemeris for maximum precision.

Every value is computed locally; no server lookups for chart math.

Real‑time engine (Swiss Ephemeris in WASM)

• Real time Positions update continuously — not precomputed tables.
• WASM WebAssembly delivers near‑native speed in your browser.
• Offline After first load, the engine and data are cached for full offline use.

Learn more about precision and the astronomy under the hood: Swiss Ephemeris — Accuracy & Why It Matters.

Zodiac systems & house systems

• Zodiac systems: Tropical, Sidereal (Lahiri/KP), True Sidereal — MTZ (constellation‑aware with Ophiuchus). See the comparison: Tropical vs Sidereal and the method: True Sidereal (MTZ Midpoint).
• House systems: Whole Sign, Equal (from Asc degree), and (with Swiss) Placidus.

Switch frames in Settings → Zodiac system and compare results instantly.

Interpretation UI: strengths, retrogrades, aspects

• Strength badges: strong / neutral / weak — a dignity snapshot to orient your reading.
• Retrograde flags: see inward‑turning planetary phases at a glance (with re‑entries logged).
• Aspect badges: ☌ 0°, ⚹ 60°, □ 90°, △ 120°, ☍ 180°, with orb and direction (↑ applying / ↓ separating).

Not sure what each symbol means? Check the FAQ section on aspect symbols and orbs.

My Life: themes, transits, and Risk & Action Weather

• Life paths: Light/Dark thematic synthesis derived from your natal picture.
• Natal themes: grouped by houses and categories for fast scanning.
• Transit→Natal blocks: context‑aware summaries explaining “what’s active now.”
• Risk & Action Weather: Money and Life gauges with a transparent “Why?” list.

Money vs Life scoring uses different weights — see details in FAQ → Scores & Risk logic.

Zeitgeist: collective climate

• Transit→Transit focus: shows the overall “weather” beyond your personal chart.
• Daily tone: quick categories and aspect clusters influencing the day’s mood.

Privacy, offline mode & data storage

• Local‑first: your inputs stay in the browser (localStorage); no account required.
• Offline mode: after initial download, charts compute without internet. When offline, use coordinates as lat,lon (e.g., 40.713,-74.006).
• Place lookup: only the name‑to‑coordinates search needs internet.

See more in the FAQ (“Basics & Offline”).

Performance & reliability

• WebAssembly engine: Swiss Ephemeris compiles to WASM for near‑native speed.
• Smart caching: once downloaded, the engine and data are reused (no constant redownload).
• Local fallback: if Swiss can’t load, AstroClock still works so you never get stuck.

Get started

• FAQ
• Zodiac Systems
• Tropical vs Sidereal
• True Sidereal (MTZ midpoint)
• Swiss Ephemeris (precision & WASM)