AstroTime

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About this app

ASTROTIME — Universal, Relativistic & Planetary Clocks

What time is it on Mars right now? How far ahead is a clock on the Moon? What
does your Unix timestamp look like in binary? AstroTime answers all of this —
beautifully, in real time.

━━━ 8 TIME SCALES, ALL AT ONCE ━━━

🌍 UTC — Coordinated Universal Time
The global civil standard. Includes your local timezone alongside UTC, and the
current Solar Longitude (Ls) of Earth in its orbit.

⚛️ TAI — International Atomic Time
The output of ~450 cesium clocks worldwide. Ahead of UTC by exactly 37 leap
seconds — with an animated historical timeline of every leap second since 1972.

🌌 TDB — Barycentric Dynamical Time
The relativistic clock at the solar system's centre of mass. Shows the periodic
±1.657 ms correction caused by Earth's orbital eccentricity — visualised as a
live sinusoidal curve.

🌕 LTC — Lunar Coordinate Time
Time on the Moon's surface. Clocks tick faster on the Moon due to weaker gravity
(+58.7 µs/day, ITU 2024). Displays accumulated relativistic drift since J2000,
current lunar phase, and all 8 phases of the synodic cycle animated in real time.

🔴 MTC — Coordinated Mars Time
Time at Mars's Prime Meridian (Airy-0 crater), calculated via the NASA Allison &
McEwen algorithm. Shows current Sol, Mars Year, Solar Longitude Ls, and an
animated dual-orbit diagram of Earth and Mars around the Sun.

💻 Unix Epoch
Seconds since 1970-01-01. Includes a live 32-bit binary representation of the
timestamp and a visual countdown to the Y2038 overflow problem.

🔭 GAST — Greenwich Apparent Sidereal Time
Earth's rotation angle relative to the distant stars. Visualised as a rotating
celestial sphere with the vernal equinox pointer (♈ Aries) moving in real time.

🌐 Internet Time (.beats)
Swatch's timezone-free decimal clock. One .beat = 1 min 26.4 s. Displayed on a
1000-division animated dial — the same moment everywhere on Earth.

━━━ KEY FEATURES ━━━

⏳ TIME TRAVEL
Enter any date and time — a birthday, a historical event, a future eclipse — and
watch all 8 clocks instantly recalculate. Includes quick offsets (±1 day, ±1 year)
and a live banner showing the moment you're exploring.

🪐 ANIMATED ORBIT DIAGRAMS
Each planetary clock includes a full-screen Canvas animation:
• Earth orbiting the Sun with current orbital position
• Moon orbiting Earth with correct phase shading and 8-phase strip
• Mars and Earth orbits compared side by side
All orbits show the correct counterclockwise rotation direction.

📖 IN-DEPTH EXPLANATIONS
Every clock includes a collapsible "About" panel with the physics, history, and
real-world use of each time scale — from Einstein's relativity to NASA mission
planning to the Y2038 computer crisis.

🌟 SPACE-THEMED DESIGN
Animated starfield background, shooting stars, per-planet accent colours, and a
dark space aesthetic built for OLED screens.

━━━ WHO IS IT FOR? ━━━

• Space enthusiasts and amateur astronomers
• Software developers curious about time systems
• Students studying physics, relativity, or planetary science
• Anyone who ever wondered what time it is on Mars

━━━ PERMISSIONS ━━━

None. AstroTime requires no permissions, no account, no internet connection after
first load. All calculations run entirely on your device.

━━━ TECHNICAL NOTES ━━━

All time calculations use published scientific formulae:
• MTC: Allison & McEwen (2000), NASA
• LTC drift: ITU recommendations (2024)
• TDB: Fairhead & Bretagnon (1990)
• GAST: IAU 1982 GMST formula
• Solar Longitude: standard equation of centre
Updated on
Jun 12, 2026

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
No data shared with third parties
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No data collected
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Committed to follow the Play Families Policy

What’s new

8 real-time clocks: Earth, Mars, Moon, atomic, sidereal & more. Time Travel included.