AstroTime

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