A New Calendar System for Martian Colonists

Created by Brad Stavanger

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There are 10 solar days per week in the Mars Colonial Calendar, numbered 0 through 9. These sols are named after the Greek version of the names for major celestial bodies in our solar system.

#	Sol Name	Meaning	Namesake Flashcard
0	Soldag	"The Sun's day"	Sol is our sun's proper name.
1	Phodag	"Phobos' day"	Phobos is the larger and closer of Mars' two moons. Named after the personification of fear in Greek mythology.
2	Deidag	"Deimos' day"	Deimos is the other moon of Mars. Named after the personification of terror in Greek mythology.
3	Hermedag	"Mercury's day"	Hermes is the Greek form of Mercury, the closest planet to the sun. He is the messenger to the god Zeus in Greek mythology.
4	Aphrodag	"Venus' day"	Aphrodite is the Greek form of Venus, the second planet from the sun. She is the goddess of love in Greek mythology.
5	Gaiadag	"Earth's day"	Gaia is the Greek name for mother earth, our home, and third planet from the sun. She is the mother of the Titans in Greek mythology.
6	Zeusdag	"Jupiter's day"	Zeus is the Greek form of Jupiter, the largest planet in the solar system, and fifth planet from the sun. He is the king of the olympic gods in Greek mythology.
7	Kronodag	"Saturn's day"	Kronos is the Greek form of Saturn, sixth planet form the sun. He is a Titan in Greek mythology.
8	Urandag	"Uranus' day"	Uranus is the sky, and is Gaia's consort in Greek mythology. He is the father of the Titans in Greek mythology. Uranus is the seventh planet from the sun.
9	Poseidag	"Neptune's day"	Poseidon is the Greek form of Neptune, the outermost planet in our solar system. Poseidon is the olympic god of the sea in Greek mythology.

There are 23 months in the Mars Colonial Calendar, numbered 0 through 22. These months are named after important (hovever not necisarily famous) scientists who do not have an SI unit named after them.

#	Month Name	Length of Month	Northern Hemisphere Season	Named After	Namesake Flashcard	Links
0	Thales	30 Sols	Winter	Thales of Miletus	One of the earliest known scientists	More about Thales
1	Bacon	29 Sols	Winter	Francis Bacon	Developed the Scientific Method	More about Thales
2	Archimedes	29 Sols	Winter	Archimedes of Syracuse	One of the greatest mathematicians of all time	More about Archimedes
3	Darwin	29 Sols	Winter / Spring	Charles Darwin	Evolution by natural selection	More about Darwin
4	Turing	29 Sols	Spring	Alan Turing	Father of computer science	More about Turing
5	Hypatia	29 Sols	Spring	Hypatia of Alexandria	First female scientist known to history	More about Hypatia
6	Noether	29 Sols	Spring	Emmy Noether	Major contributions to abstract algebra and theoretical physics	More about Noether
7	Galen	29 Sols	Spring	Aelius Galenus	Father of modern medicine	More about Galen
8	Kepler	29 Sols	Spring	Johannes Kepler	Developed the laws of planetary motion	More about Kepler
9	Descartes	29 Sols	Spring / Summer	Rene' Descartes	Father of modern western philosophy	More about Descartes
10	Hodgkin	29 Sols	Summer	Dorothy Hodgkin	Developed protein crystallography	More about Hodgkin
11	Lavoisier	29 Sols	Summer	Antoine Lavoisier	Father of modern chemistry	More about Lavoisier
12	Bohr	29 Sols	Summer	Niels Bohr	Major contributions to the understanding of atoms and quantum mechanics	More about Bohr
13	Elion	29 Sols	Summer	Gertrude Elion	Developed the first antiviral and immunosuppressive drugs	More about Elion
14	Wu	29 Sols	Summer	Chien-Shiung Wu	Major contributions to nuclear physics	More about Wu
15	Mendel	29 Sols	Summer	Gregor Mendel	Father of modern genetics	More about Mendel
16	Linnaeus	29 Sols	Summer	Carl Linnaeus	Naturalist. Father of binomial taxonomy	More about Linnaeus
17	Burnell	29 Sols	Summer / Autumn	Jocelyn Burnell	Discovered the first radio pulsar	More about Burnell
18	Moseley	29 Sols	Autumn	Henry Moseley	Proved the concept of atomic number and created periodic table of the elements	More about Moseley
19	Oersted	29 Sols	Autumn	Hans Oersted	Discovered electromagnetism	More about Oersted
20	Hutton	29 Sols	Autumn	James Hutton	Father of modern geology	More about Hutton
21	Laplace	29 Sols	Autumn	Pierre-Simon Laplace	Major contributions to calculus. First person to postulate the existance of black holes	More about Laplace
22	Sagan	29 Sols (30 on leap years)	Autumn / Winter	Carl Sagan	Profound science communicator. Cosmologist, astrophysicist, astrobiologist, and astronomer	More about Sagan

Purpose

Calendar systems have been developed and used on earth since the dawn of civilization. Created by man to predict the behavior of the natural world around us, calendars have also shaped the behavior of mankind. Calendars have been used to espouse the values of a culture, celebrate individuals, and structure routine into human society. The creation of a new calendar should be done with care, because it will have a real world effect on those who adopt it. Calendars are about more than just keeping time.

The Problem

There have been several Martian calendars proposed; some references in fiction originate from books published the 1800's. Several more new Martian calendars have been developed using math and astronomical data to make accurate timekeeping and keep chronological slippage to a minimum. After reviewing these individual attempts in Martian calendar making, I have found them all to be, in a word: uninspiring. I have also found several calendars to be simply inaccurate. More broadly, these calendars tend to be unimaginative, copying names and numbers straight from earth calendars. I needed a coherent, interesting, and accurate system for my book, so I have made my own.

Division of Time

Whatever the original intentions for the divisions in our calendar were at the time of it's conception, we can see the impact of having weeks, months, and years in our lives. These divisions have sculpted modern human behavior, giving a series of beginnings, middles, and ends for humans to keep rhythm to.

"Days" are the basic unit of a calendar because it ties to a deeply ingrained biological function of the human body; we are drawn to sleep at night and are active in the light. Days are one of the few things that every calendar agrees on. In the case of Mars, a calendar maker needs to take a slight departure from the "day," because mars spins on its axis slightly slower than earth, as well as orbiting slower around the sun, significantly changing the length of a solar day. To avoid confusion, a solar day on mars is referred to simply as a "Sol" in science and literature.

An average sol on mars lasts 24 hours 39 minutes and 32.244147 seconds between one sunrise to the next sunrise. This value is not reconcilable with the 24 hour clock used on earth. In Kim Stanley Robinson's novel "Red Mars", the Martian colonists used 24 hour clocks that simply froze in stillness for those 39+ minutes each day, creating a timeless moment for people. While this concept is socially interesting, it would be disastrous for any serious endeavors that required precise timing during this period, resulting in the need for a second time system anyways.

One possibility I explored and abandoned was the elimination of the traditional hours, minutes, and seconds (which are all mathematical divisions of an earth day) and replacing them with new divisions. There were several reasons this was not a good idea, but the most important reason for me personally, is that changing the length of the "second" would mean breaking compatibility with the metric system; and I find that to be unacceptable. We can't create an entirely new scientific measuring system every time we colonize a new planet. "4.5 meters per second? Is that in earth seconds, Martian seconds, or Europan seconds?" For better or worse, we are stuck with earth "seconds" being the basic unit of time.

For simplicity's sake, after deciding to keep the second, the minute and the hour will be kept as well to avoid confusion with earth terms. This leaves the Martian Clock with a peculiar division, where it is reset to zero after reaching approximately 24:39:32.25. I believe that this is a low price to pay in order to preserve the metric system. It is also very easy to represent on a digital clock, requiring no additional hardware, just a software change.

What about larger divisions of time? The week? The Month?

What is the point in having these week and month divisions in a time keeping system? The week was originally designed after religious tradition to remind Jewish worshipers of the creation mythology in Genesis, and to set a time to bring individuals to the church for ceremony. This, in practicality, ended up defining the rhythm of our work schedule, by having a 'sabbath' where it was -more or less- illegal to work. It is often common to refer to our "work week" in modern parlance, or "taking a long weekend off work". The week is how modern society organizes it's labor, and it is a useful tool for describing our work/life cycle. The Mars calendar is divided into 10 day 'weeks'.

The month is perhaps a less arbitrary unit of time than the week. Earth months are modeled after the lunar cycle; quite literally 'Moonths' if you will... There are (approximately) 12 cycles of the moon in an earth year. How would this apply to Mars? Well, simply put, it doesn't. The major moon of Mars circles the planet multiple times a day, where in some cases an individual could see two moonrises in a single solar day. Instead, lets consider the other implication of the lunar cycle. Somehow, either through coincidence or evolution, the human reproductive cycle is closely tied to earth's lunar cycle, typically being 21-35 days. Aside from biological reasons, the month has become a major period of accounting in human society, where rent, payments, and interest are all calculated upon it. Compared to the week or year, it is a useful medium length of time to base goals upon.

So how long should a Mars month be? Since the Martian year is a little over 668 days, I found that 29 sols divided into 23 months equals a 667 sol year, which is only a single sol short of being equal to 668 sols. So the first month of mars gets an extra sol, making it 30 sols long. The Mars year is actually 668.5991 sols long. This leaves a pesky ~3/5 of a sol extra at the end of each year. This is easily addressed by leap years. The last month of the Martian year gets an extra sol on leap years, which occur on a 5 year pattern of: normal year, leap year, normal year, normal year, leap year, and repeat. This will keep temporal slip to less than a single sol for over 1000 Martian years, at which point an exception to the leap year rules can be made at every 1111th year. And as for those who care, an exception to the exception can be made at year 9999. So, remarkably, the death of this calendar system will be Mars' own orbital precession, and not a failure of the calendar itself.

Names in the Calendar

Now that the time devisions for seconds, minutes, hours, sols, weeks, months, years, and leap years have been worked out... what or who do we name the months and weekdays after?

When the Julian calendar was created, the months were named after people Julius Caesar wanted to celebrate. Similarly, I have borrowed from this tradition. For the 23 Months of Mars, I have decided to name months after modern and ancient scientists who do not have the honor of having an SI unit of measurement named after them, but who have contributed greatly to humanity's understanding of the universe. Some may wish to argue with me over my choices of who made this list, and I certainly did not honor all that merited such credit, but hey, I'm human, and this is my calendar, so I call the shots.

The name for weekdays significantly vary from language to language on earth. At least for English, the weekday names were scavenged from previous mismatched pagan traditions, with some days named after the sun and the moon, and others after gods in Norse mythology. For the 10 sols of the Martian week, I have decided to name them after major celestial bodies in our solar system, as well as the two moons of Mars, but all nomenclature is kept consistent to Greek Mythology. I felt this was consistent with the idea of naming weekdays after both celestial bodies and mighty mythological beings.

What is with "Zeroth"

A purely asthetical choice was to consider the first instance of an hour, or sol as the zeroth hour, or the zeroth sol. The month does not start with one whole sol already behind you, so the begining of the month starts at sol 0. The begining of the year starts at month 0. It also ties in very nicely into computer science standards where indexed lists start at 0. Base 10 math does not run from 1 to 10, but rather, it runs from 0 to 9 and my system reflects this reality.

When does the Martian Calendar Begin?

As this calendar was made for a fictional novel, I was tempted to place the Martian calendar epoch at some time in the future, based on events in the book. I decided against this idea because it would limit the significance of this calendar to just my fictional universe. If this calendar system was to ever used for a real Mars colony, it would need a justifyable begining.

Looking for the first time that humans had interacted with the planet Mars, I knew that the Viking Landers were the first probes to successfuly land on mars and send back data. So I had the option of starting the calendar epoch at the time the Viking 1 made touchdown. However, this was not the first time a manmade object reached the surface of Mars.

Before Viking 1, the Mars 2 probe crashed on Mars after some complications. This is the first time humans had an impact on Mars (pardon the pun). By starting the calendar from a date of a mission failure, the Martian epoch also emphasizes to any future Mars colonists: Humility, Courage, and Perseverance.

Formal Proposal for the Martian Epoch

The Mars Calendar Epoch begins when the Mars 2 lander crashed into the surface of Mars, becoming the first man made object to touch the surface of Mars, at 4N 47W. I propose that 47W becomes the official Prime Meridian of Mars. Mars 2 reached Mars on November 27, 1971. The lander separated from the spacecraft at 15:44 UTC. The spacecraft captured orbit around 20:19 UTC (a little over 4 1/2 hours later). The lander crashed on the surface at nearly the same time after a 3 minute descent through the atmosphere. I am estimating the landing time to be 20:22 UTC. I propose that the Martian calendar begins at this moment.