A Proposed Calender for Space Settlers

NB. My proposed calendar is not intended to replace any calendar in use here on Earth.


The Gregorian calendar which is the mostly used in contemporary society is not quite suitable for Space Settlements. Therefore we will propose a new calendar to be used in space colonies. Why is our current calendar unsuitable for space colonies? There are several arguments against the Gregorian calendar, one of them is that it is not a perpetual calendar, which means that each year starts on a different year. Further it is a very strange idea to base the calendar of a space colony on the earth’s seasonal cycle, while space settlers are in full control of the length of their days and thus of their seasonal cycle. Therefore there is no need for adjusting the calendar of a space based society to the solstice.


Our proposal is based on Irv Bromberg’s Symmetry454 calendar, with a few modifications. According to this plan each year is divided into four quarters, which are divided into three months. The first and third have each four weeks, the second has five. Like our current calendar the symmetry454 calendar preserves the seven-day-week, which in my opinion an important feature. However as I have said, I have a few amendments.

Bromberg has proposed to start his calendar on Monday January 1, 2005 in order to ensure that each year starts at a Monday. Our suggestion is to start our calendar on Thursday January 1, 1801. Why this date? On this date Giuseppe Piazza discovered Ceres, the first asteroid known by humanity. Since asteroid mining is the key to space colonization, this particular event of immense significance of every space based civilization. This will have as a side effect, that each year will start on Thursday and end on a Wednesday, however we do not consider this as a big issue. We could simple make Wednesday as the civil rest-day, of course anyone who wants to keep Sabbath on Sunday (or on Saturday or Friday) will be free to do so.

By changing the start of the calendar we can also use this opportunity to implement a fully secular year counting, which is important given our commitment to Secular RepublicanismIn our proposal the year 1801 AD will be year 0 Anno Cereris, all years before will be referred to as minus <year> Anno Cereris.

Another amendment we want to suggest, is to get rid of leap years. As I have explain above, space settlements have no reason to adjust the calendar to earth’s seasonal cycle. Therefore we do not have any need for leap years. This is quite a difference for Bromberg’s proposal, in which once in the five or six years there would be a leap week (to be calculated according to a rather complicated formula).

Of course having a year with just 364 days and no leap years, will have as a consequence that our years will run faster than “terrestrial” years. This is however no real problem, the proposed calendar for Mars colonies runs significantly slower than Earth’s, but until know I have not the impression that this a big issue among Mars enthusiasts.

Days of the week

Our proposal for the days of the week is to name them after the colours of the rainbow. Thus: Thursday will be “Red day”, Friday “Orange day”, Saturday “Yellow day”, Sunday “Green day”, Monday “Blue day” (no irony intended), Tuesday “Indigo day” and Wednesday “Violet day”.

Names of the months

In order to prevent confusing, we should give the months of our calendar different names as those of the Gregorian calendar. However we have no particular proposal for these, but our suggestion is to begin their names with A, B, C, D, E, F, G, H, I, K, L and M respectively. This in order to make it easy to distinguish them when abbreviated.

13 thoughts on “A Proposed Calender for Space Settlers”

  1. why not have the counting start with the first space colony, and any years before that to be treated minus as you suggest. And can months be ignored in the counting?

    1. why not have the counting start with the first space colony

      In fact I have considered this one, but it would mean that most people would have negative years of birth. This would not be bad for historians, but is quite odd for the living.

      And can months be ignored in the counting?

      I am quite sympathetically to this idea, you would then get dates such as (day) 167 / (years) 34. However, it’s my guess that the overall majority would like to maintain the concept of months. But personally, I wouldn’t mourn if we should abolish months.

      1. It doesn’t have to be negative. They will just have been born before the colony was established just like the Muslims count from the supposed migration by their supposed prophet.

        In retrospect, omitting months would complicate the counting, unless the concept of years is done away with too

        1. Months might seem strange from a strict rational point of view, but they are quite practical in daily affairs. A day counting calendar, such as the Julian Day Number system (see: http://en.wikipedia.org/wiki/Julian_Day_Number) will lead to dates with very large numbers, which isn’t practical.

          Another thing is the seven-day week, nothing logical about it, but I think a schedule of 5 workdays – 2 rest days is a good rhythm for humans. Attempts has been made to get away with the 7-day week, all of them were unsuccessful.

  2. I’ve had to deal with this problem in my science fiction novels for a calendar created by space traveling aliens. Gene Roddenberry had to deal with it for Star Trek as you know, and came up with “stardates” [ http://en.wikipedia.org/wiki/Stardate ]. During my research I considered other names for the days of the week and read this article [ http://en.wikipedia.org/wiki/Names_of_the_days_of_the_week ]. This [http://en.wikipedia.org/wiki/Week#Eight-day ] made a big impression on me because the alien characters in my stories are basically known as merchants. So, relating to, “The ancient Etruscans developed an eight-day market week known as the nundinal cycle around the 8th or 7th century BC. This was passed on to the Romans no later than the 6th century BC. As Rome expanded, it encountered the seven-day week and for a time attempted to include both. The popularity of the seven-day rhythm won and the eight-day week disappeared.” Apart from the calendar issue, is the relating issue of the so-called work week. How long should it be? How many hours per day? Perhaps it ties in with health and environment. Maybe humans in space, as well as on asteroids, or Mars, or the Moon, will need to rest and refuel more often, or perhaps less. Maybe that could in some way effect the calendar and clock to be used by them, such as for work days. If families go out there, and children are brought up out there, then of course education becomes part of the issue. School all year? A one-week break every quarter of year? Perhaps the same for their working parents, so school and work vacation times mesh. It’s all about time management. By the way, it was just 2 years ago when I found articles at Wikipedia [ https://en.wikipedia.org/wiki/Common_Era ] using CE instead of AD for Common Era, and BCE instead of BC for Before Common Era. That difference turned out to be perfect for the alternate history timeline revision I developed for the new version of my novels. What was most surprising to me is that the use of CE and BCE began in ancient times! How did I ever miss that little detail of history? The older I get the more I realize how useless most of school was most especially during elementary school at the public school I attended. Most of what I use as an adult from what I learned during school years 1 to 6 could have been taught in 1 year, even to just a C-average student in a better time-managed education system. Mainly basic math, reading, and writing, I mean. But of course I’m now ranting on a different issue. So I’ll leave the comment at this point with that food for thought for future posting subjects we should also write about.

  3. Assuming you are a colonist who is not on earth, what vestiges of earth time would you need to bring along? I’d say just the Year and the Hour (and measurements smaller than an hour). The division of days and months will depend on your locality. Some divisions will be more practical for some places and not for others.

    MAYBE, include the 24/25 hour day, because humans have evolved to run on days of this length, but these may have no place in an extra-terrestrial calendar if it does not match with the local night/day cycle.

    And include Years, so people can still cite their age in Earth Years regardless of if the planet they inhabit takes 4 or 0.4 Earth Years to cycle its star.

    Simple (and somewhat fun) conversion: 1 (Earth) Year = 8765.4321 Hours. But I am sure you could round it off somewhere.

    1. Thanks for your comment.

      The division of days and months will depend on your locality. Some divisions will be more practical for some places and not for others.


      but these may have no place in an extra-terrestrial calendar if it does not match with the local night/day cycle.

      And include Years, so people can still cite their age in Earth Years regardless of if the planet they inhabit takes 4 or 0.4 Earth Years to cycle its star.

      From this it appears to us, that you are thinking about colonies on planetary or lunar surfaces. However, that is not the kind of Space Settlements we want to establish. Instead of colonizing planetary or lunar surfaces, we want to build space habitats in free space, orbiting our Sun.

      In such a space habitat we have full control of our local night/day cycle, by means similar to moving the curtains in front of your bedroom window. And since humans have been evolved with 24-hour days, it will be a logical option to choose cycles of 24 hours. Further we can also regulate the seasonal cycle by playing with the length of days, and we can give this cycle any length we wish.

      1. I see. So, if none of our month, day, and year lengths are tied to Earth’s, then why not just have a 360-day calendar? That would be so much easier and simpler.

        Hmm… I suppose that would not “mesh” with a 7-day week. Some Sacred Cows just won’t die. You could always go to a 420-day calendar.

        1. One thing to consider is that though our settlements will be in outer space, they will heavily depend on trade with Earth. Secondly many of the first settlers will have difficulties with adapting to life in space, so by keeping the amount of change small will ease this process.

          And concerning the 7-day week, I believe that this length is well suited for human psychology.

  4. I do hope you are giving out the calendars for free. My bank always gives me 2 or 3 with lovely pictures and a big space to write in.

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