Mars Calendar

Timekeeping on Mars

Few years back I noticed that new year will start on Mars. I started to think about timekeeping on Mars. How long its year is, how long is a sol (Mars day)? How would one have the months, since Mars doesn’t have a proper moon for such division?

Quickly, I compiled a calendar, since the new year was coming. It was for the Mars year 36. (First Mars year started in 1955 in our calendar.) I wasn’t too happy with the result, the time ran out. So I decided to try again next year. This time there was plenty of time, since Mars’s year lasts almost two Earth years. The year 37 in Mars started in 26th December 2022 and will last until late 2024. And my calendar was ready.

This calendar is in Finnish only. It shows 18 calendar spreads, divided into seasons and ”quadragesimals” or ”quarants”. (There is no official agreement about how to divide Mars’s sols into segments, so I just used groups of 40 sols in four seasons. The last 40 sol segment in each season falls short.) I also calculated the anniversaries of different Mars probes and added them into the calendar. (The anniversaries – as everything else in the calendar – are in Mars years. The calendar is areocentric.)

To make the calendar more interesting, I added pictures from NASA etc. from Martian landscapes with info, as well as short presentations of different probes. There’s also a chart of the inner solar system in each spread that shows the positions of earthlike planets around the Sun in the beginning of that ”quarant”.

Still, the bread and butter of the calendar are the presented views of Martian skies in each spread. The calendar shows the most interesting objects in the sky, as if the user would be an amateur astronomer living on Mars. The pictures I drew with the help of Stellarium planetarium programme. The info I hand-picked from the data.

The calendar turned out nicely, but the amount of work was insane. The best part was that planning and working with this really took me into Mars, thinking how it would be like over there. It also gave perspective to what Earth is like – in many calendar spreads the Earth is the brightest object in the Martian sky, even Moon is visible with your naked eye in certain time of the year.

I printed few calendars for sale. I’m not sure if I’ll get inspiration for Mars year 38, though.

You can download the calendar for yourself from here. It is in Finnish only, and there won’t be an English translation.

The shop Alnilam might still have a copy for sale. If you are interested, you can ask them directly: