For non-Earth positions, enter location JSON:
Leave blank to disable. No request is made if empty.
Connect your own API key for enhanced reasoning. API keys are stored locally only and never sent to InterPlanet servers.
Provides plain-language recommendations after Best Windows. Leave blank to disable.
Leave blank to disable weather data. Default: open-meteo.com
Each planet gets a 24-hour clock based on its own solar day — one sunrise to the next. Mars sols are 24 h 39 m long; Jupiter days are just 9.9 h. InterPlanet divides each planet day into 24 equal local hours and applies a 5-day work week with 8-hour shifts, so every world has a familiar concept of 'work time' and 'rest time'. Mars Coordinated Time (MTC) anchors to the J2000.0 epoch (1 Jan 2000, 12:00 UTC). Exception: Mercury and Venus have solar days of ~176 and ~117 Earth days respectively — far too long for solar-day scheduling. Crews on these bodies follow an Earth-clock schedule: Mon–Fri UTC 09:00–17:00. MMT and VMT timezone zones identify geographic location only.
Radio signals travel at the speed of light — 299,792 km/s. At its closest, Mars is ~55 million km away (about 3 min one-way). At its farthest it's over 400 million km (~22 min). Jupiter ranges from 35–52 min; Saturn from 68–85 min. During solar conjunction — when the Sun sits between Earth and the target planet — signals are blocked for 1–2 weeks. InterPlanet calculates live delay using Keplerian orbital mechanics (±3–8% accuracy).
The sky gradient reflects local solar altitude: deep indigo at night, warm reds at dawn and dusk (Rayleigh scattering), pale blue at noon. Mars' iron-oxide dust scatters red wavelengths, producing its characteristic butterscotch sky. Real cloud cover data from Open-Meteo darkens the gradient. The highlighted segment on the hourly bar shows where you are in the planet's current day.
InterPlanet implements the proposed InterPlanet Time (IPT) standard, aligned with
RFC 9557 (IANA timezone extensions) and IAU/IERS planetary conventions.
The 25 Mars AMT zones follow the same 1-hour offset structure as Earth's UTC offsets.
The LTX meeting protocol (Light-Time eXchange) extends RFC 5545 iCalendar with
LTX-* properties designed for high-latency structured sessions.
Try an LTX meeting →
See what time it is anywhere on Earth — and on other worlds. Compare cities, planets, and space missions on one timeline.
Or try a quick demo: