One of the first people I met from the Mars Society when I joined back in 1999 while living in the Netherlands, was Frans Blok. An architect, Frans had designed something called the "Darian Defrost Calendar", based on a very good Mars calendar called the Darian Calendar, designed by Tom Gangale. I found both the Darian Defrost and the Darian Calendars fascinating.
The idea that there could be a calendar for Mars hooked me into the idea of Mars settlement. Along with the Mars trilogy by Kim Stanley Robinson, it helped to make Mars a real place in my imagination.
The Darian Defrost Calendar is the same as the Darian Calendar except that it uses different names for the months of the year, and different names for sols of the week. The names follow a clever alphabetical pattern, each beginning with a unique letter of the alphabet, from A to Z. Accompanying each month of the calendar is a colourful map showing a quadrant of a future terraformed Mars.
The concept of a calendar for Mars really caught my imagination and I began to study and think about this question. I discovered Tom’s Martian Time website, which details virtually every known Mars calendar and timekeeping system ever developed, whether from science fiction or as a serious proposal for use on Mars.
After looking at some of the existing proposals for Mars calendars, I began experimenting with my own variations and designs, and weighing up the pros and cons of different choices, such as:
- number and length of months and weeks
- names for months and days of the week
- whether or not the calendar should even have months or weeks
- starting point of the Martian year
- starting point of the Martian epoch
I also joined a “Mars Time” mailing list that had been created by Bruce Mackenzie and Gary Fisher of the Mars Society, and participated in discussions on that list.
In 2000 an online role-playing game and micronation appeared called the “Republic of Mars” (RoM). This was a non-graphical and non-commercial game composed primarily of online forums, Yahoo groups, and various small websites created for imaginary Martian colonies, companies, and so on. The “players” role-played a group of settlers that had arrived at Mars and had set themselves a goal of creating a new Martian “nation”. As they experiment unfolded during the 1-2 years of its lifetime, the group created a constitution, laws relating to terraforming, a number of colonies (each with their own unique website), Martian companies such as the Mars Bank and Mars Telecoms, Mars University, and various other elements of a burgeoning Martian civilisation.
One of my contributions was to create the “Mars Time Group” comprising RoM players where were interested in this topic, and lead the discussion about creating the optimal calendar for Mars. I’d already developed a Mars calendar called the “Areosynchronous Calendar” for an earlier project of mine called Virtual Mars. With additional study of the Martian Time website, and discussion of various points within the Mars Time Group and the Mars Time mailing list, this was tweaked and became the Utopian Calendar, also briefly known as the Kepler Calendar.
The Utopian Calendar became the official one for RoM, and was also adopted by the Mars Simulation Project and a computer game called Martian Dreams. The Martian Calendar app for Apple Watch by Laurie Harrison features the Kepler Calendar, which is very nearly identical to the one presented here.
The other alteration relates to the epoch, which means, at what point in time are mirs counted from (in the Gregorian Calendar, they are counted from the birth of Christ; or at least, that was the intention). In the Utopian Calendar, the epoch (mir 0) begins with the advent of telescopic observation of Mars in 1609, which means the Martian dates of all telescopic observations of Mars occur in a positive mir. The epoch of Tom’s calendar began about the time of the Viking landers, such that the Martian dates of all lander missions would have a positive mir. Tom changed the epoch of the Darian Calendar to match the Utopian Calendar, and called this the “Telescopic Epoch”. With these changes, our calendars aligned mathematically. The names of days of the weeks, and of months, remained different, however, these are really just the paint job.