Martian Calendar 4+

Laurie Harrison

Designed for iPad

    • 3.7 • 3 Ratings
    • $0.99


The application shows the calendar date for Coordinated Mars Time (MTC) and Coordinated Universal Time (UTC) as well as your device’s Local Time (Local), with the ability to select between some popular calendars proposed for Mars.

Martian Calendar Information

Fast Forward About 75 Years. You are probably middle-aged (because life expectancy has grown) and one or more of your kids may be preparing to leave for a colony on Mars. There is a good chance this could happen in your lifetime - or at least in the lifetime of your kids or grandkids. This app will help you start thinking like a future Terran with ties to a Mars colony.

Calendar Dates

Straightforward, right? Not so much. Scientists have been debating how best to keep track of time and days on Mars for the past century. And, while the debate is converging on some solutions - it’s far from finished! Check out the settings below so you can participate in this historic debate - it isn’t every generation who gets to literally shape time!

SOL: A day on Mars is called a sol, and is about 2.7% longer than a day on Earth, at about 24 hours, 39 minutes and 35.24409 seconds long. For convenience, timekeeping on Mars assumes that a sol is exactly 24 hours long, just like on Earth, except that each time unit on Mars is 2.7% longer than on Earth.

EPOCH: Astronomers keep track of a count of days for Earth called the Julian Day Number - which is just a count of days from a specific date in history called an epoch. For example, the Julian Day Number for January 1, 2000 is 2,451,545. Likewise, for Mars there is a Mars Sol Date (MSD) which is a count of sols from a specific epoch.

CALENDAR: The Mars year is 668.5907 sols long, so a year in a Mars calendar will typically contain either 668 sols or 669 sols (if it is a leap year). Many different calendar structures have been proposed over the last century, with different characteristics. For example, Thomas Gangale created the Darian calendar with a structure of 24 months of mostly 28 sols per month (there are four with only 27 sols, but in leap years this goes down to 3). The Kepler calendar uses the same structure as the Darian calendar but names the months and sols differently, and does not skip over a sol during months 6, 12 and 18 like the Darian calendar.

TIME DISPLAYS: To FaceTime your kids without waking them, you’ll need to know the time on Mars as well as on Earth. The application shows the official times of both planets:
- MTC: Mars' official time, called Coordinated Mars Time (MTC) (also known as Airy time),
- UTC: Earth's official time, called Coordinated Universal Time (UTC).

It also shows the time most of us use today:
- LOCAL: Your device’s local time.

OK - You’re all set to imagine yourself in an exciting new future - and pretty well prepared to jump into an historic debate. The links below will take you even farther into the future. Happy travels!


What’s New

Version 3.0

Adds support for watchOS complication to show MTC (Mars Time).
Adds support for iOS to convert a local date and time to all supported Martian calendars.

Ratings and Reviews

3.7 out of 5
3 Ratings

3 Ratings

GianniTriCity ,

Martian Calendar

This is the best, and only, Martian calendar for iOS and now watchOS! Now my Mickey Mouse watchface can tell me today is Thursol, 11 Capricornus 27, in the Mariner calendar! I'm readily amused….

LifeLover13 ,

Great concept, needs more

This isn’t exactly a calendar, but more like a watch. Here are my suggestions for improving the app:

1) more explanation on how to read this information. It’s pretty bare bones. There’s not even any information on the Mariner calendar.

2) make it an actual calendar, like the way we can view an earth calendar and see all the days, flip back and forth, count the days in each month, etc.

I love the time features of this and the general concept!

App Privacy

The developer, Laurie Harrison, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Not Collected

The developer does not collect any data from this app.

Privacy practices may vary, for example, based on the features you use or your age. Learn More


  • Family Sharing

    Up to six family members can use this app with Family Sharing enabled.

More By This Developer

You Might Also Like

Dash View for Tesla Cars
@Beat: Internet time
Level Sense Sump Pump Monitor
Thinkware Connected
AirGap Vault - Secure Secrets