Martian Calender - I have created a martian calender...

RobertDyck · 2016-01-01 14:52:02

One month was based roughly on one orbit of Earth's Moon. The synodic period of the Moon is 29 d 12 h 44 min 2.9 s, so there are 12.3687 lunar months in a year. That was rounded off to 12, with various adjustments to do that. The first Roman calendar was created by Romulus, had 10 months:
Martius (31 days) - named for Mars, believed to be father of Romulus and Remus
Aprilis (30 days) - became April
Maius (31 days) - became May
Iunius (30 days) - pronounced "Junius", became June
Quintilis (31 days) - "quin" is Latin for the number 5, so this means 5th month
Sextilis (30 days) - "sex" means 6
September (30 days) - "septem" means 7
October (31 days) - "octo" means 8
November (30 days) - "novem" means 9
December (30 days) - "decem" means 10

this resulted in 304 days per year. They realized very quickly this wouldn't work, came up with a new calendar. Numa came up with a new calendar, inserting 2 more months:
Ianuarius (29) - pronounced Januarius
Februarius (28)
Martius (31) - named for Mars, became March
Aprilis (29)
Maius (31)
Iunius (29) - pronounced Junius, became June
Quintilis (31)
Sextilis (29)
September (29)
October (31)
November (29)
December (29)
This resulted in 355 days. Well, it still isn't 365, but it's better. Notice Quintilis through December still have the same names, but now "decem" is Latin for 10, but December is the 12th month. Oops.

This was further refined by emperor Julius, called the Julian calendar. Effective year 45, he gave the months the number of days we have today. Complete with leap years: 29 days in February every 4th year. That means 365.25 days per year. Very close, the Gregorian calendar only added minor tweaks. Julius also renamed the 7th month after himself; instead of Quintilis (meaning 5) he called it Iulius (Latin spelling), pronounced Julius. That became July.

So why can't we be just as creative? We can divide the number of solar days on Mars into useful groups. And give them names. We don't have to continue to call the 12th month by the Latin word for 10.

louis · 2016-01-01 19:36:52

I agree - no need to stick with the rickety Roman structure.

But I would like to have a connection to the seasons - especially over such a long orbit. So I would recommend we divide the Martian year up into defined quarters and then sub-divide those four seaonal periods of 167 sols into 16 "ten sol" periods (also divided into 4 terms of four tensols) followed by a 7 sol festival period to mark the solstice/equinox.

So in the run up to the Summer Solstice (which might be designated a particular festival, e.g. perhaps the "Festival of Exploration") would be four terms - First, Second, Third and Fourth (each comprising four tensols) - leading up to the Festival.

A "tensol" or "decisol" would become the week on Mars but would comprise two work periods of three days with either one or two day breaks between the three day work periods.

So when you looked at your watch it might read:

5/3/4/2/34

5 = Fifth Sol (out of 10 sols in a tensol)

3 = Third Tensol (out of 4 tensols in a term)

4 = Fourth Term (out of 4 terms plus the seven sol Festival in a season)

2 = Second Season (out of 4 seasons in a Mars year)

34 = Mars Year 34 (34 years since the first landing of humans on Mars).

RobertDyck wrote:

One month was based roughly on one orbit of Earth's Moon. The synodic period of the Moon is 29 d 12 h 44 min 2.9 s, so there are 12.3687 lunar months in a year. That was rounded off to 12, with various adjustments to do that. The first Roman calendar was created by Romulus, had 10 months:
Martius (31 days) - named for Mars, believed to be father of Romulus and Remus
Aprilis (30 days) - became April
Maius (31 days) - became May
Iunius (30 days) - pronounced "Junius", became June
Quintilis (31 days) - "quin" is Latin for the number 5, so this means 5th month
Sextilis (30 days) - "sex" means 6
September (30 days) - "septem" means 7
October (31 days) - "octo" means 8
November (30 days) - "novem" means 9
December (30 days) - "decem" means 10
this resulted in 304 days per year. They realized very quickly this wouldn't work, came up with a new calendar. Numa came up with a new calendar, inserting 2 more months:
Ianuarius (29) - pronounced Januarius
Februarius (28)
Martius (31) - named for Mars, became March
Aprilis (29)
Maius (31)
Iunius (29) - pronounced Junius, became June
Quintilis (31)
Sextilis (29)
September (29)
October (31)
November (29)
December (29)
This resulted in 355 days. Well, it still isn't 365, but it's better. Notice Quintilis through December still have the same names, but now "decem" is Latin for 10, but December is the 12th month. Oops.
This was further refined by emperor Julius, called the Julian calendar. Effective year 45, he gave the months the number of days we have today. Complete with leap years: 29 days in February every 4th year. That means 365.25 days per year. Very close, the Gregorian calendar only added minor tweaks. Julius also renamed the 7th month after himself; instead of Quintilis (meaning 5) he called it Iulius (Latin spelling), pronounced Julius. That became July.
So why can't we be just as creative? We can divide the number of solar days on Mars into useful groups. And give them names. We don't have to continue to call the 12th month by the Latin word for 10.

Last edited by louis (2016-01-01 19:47:46)

SpaceNut · 2016-01-01 22:19:56

668 sols divided by 2 equals
334 sols for half a year then divided by 2 equals
167 sols for each season

But this is the Mars seasons time frame posted next:
Spring…7 months, Summer…6 months, Fall…5.3 months, and Winter…just over 4 months.

The way that scientists mark the time of Mars year is to use solar longitude, abbreviated Ls (read "ell sub ess"). Ls is 0° at the vernal equinox (beginning of northern spring), 90° at summer solstice, 180° at autumnal equinox, and 270° at winter solstice.
Mars is at aphelion (its greatest distance from the Sun, 249 million kilometers, where it moves most slowly) at Ls = 70°, near the northern summer solstice, and at perihelion (least distance from the Sun, 207 million kilometers, where it moves fastest) at Ls = 250°, near the southern summer solstice. The Mars dust storm season begins just after perihelion at around Ls = 260°.

That said by looking at the numbers the only mark is a half year the lines up for the months totals on winter/spring or for summer/fall but its the length of the seasons that do not line up for the next interval of division of 2.
The orbit of mars is very egg shaped.

What I am trying to figure out is why the window to launch from earth is 2 yrs 7 weeks (779 days) when the mars sols are 668 (684 Earth days) in a Martian year.

RobertDyck · 2016-01-02 00:45:57

SpaceNut wrote:

What I am trying to figure out is why the window to launch from earth is 2 yrs 7 weeks (779 days) when the mars sols are 668 (684 Earth days) in a Martian year.

Earth doesn't stay put, our planet orbits the Sun too. It's a matter of the two planets lining up with each other.

Cosmic Train Schedule - assume Hohmann transfer orbit = 8.5 months. This table uses some simplifications for calculations, so dates are approximations.

This next schedule assumes also assumes a Hohmann transfer orbit. The lower chart shows solar cycle as a sin wave; higher means more solar radiation but less GCR, lower means lower solar radiation but more GCR. And the bars indicate likelihood of dust storms. They're perfect bars so that should tell you they're rough approximations.

Last edited by RobertDyck (2016-01-02 19:29:25)

louis · 2016-01-02 18:19:14

Sorry I was forgetting about Mars's eccentricities (incidentally, I understand Mars's seasons aren't so pronounced either because of the axis wobble). However I don't think our "official" solstices/equinoxes line up exactly with orbital distance (there is a few days' difference I believe). So, I would prefer to stick with even divisions, even if they don't line up exactly with orbital distance.

On the launch window issue - that relates to Hohmann (?) Transfer Orbits, doesn't it? So, presumably it's some sort of interaction between Earth and Mars Orbits (and don't the launch windows vary significantly i.e. are you sure the window is always 779 days?).

SpaceNut wrote:

668 sols divided by 2 equals
334 sols for half a year then divided by 2 equals
167 sols for each season
But this is the Mars seasons time frame posted next:
Spring…7 months, Summer…6 months, Fall…5.3 months, and Winter…just over 4 months.
The way that scientists mark the time of Mars year is to use solar longitude, abbreviated Ls (read "ell sub ess"). Ls is 0° at the vernal equinox (beginning of northern spring), 90° at summer solstice, 180° at autumnal equinox, and 270° at winter solstice.
Mars is at aphelion (its greatest distance from the Sun, 249 million kilometers, where it moves most slowly) at Ls = 70°, near the northern summer solstice, and at perihelion (least distance from the Sun, 207 million kilometers, where it moves fastest) at Ls = 250°, near the southern summer solstice. The Mars dust storm season begins just after perihelion at around Ls = 260°.
That said by looking at the numbers the only mark is a half year the lines up for the months totals on winter/spring or for summer/fall but its the length of the seasons that do not line up for the next interval of division of 2.
The orbit of mars is very egg shaped.
What I am trying to figure out is why the window to launch from earth is 2 yrs 7 weeks (779 days) when the mars sols are 668 (684 Earth days) in a Martian year.

louis · 2016-01-02 18:20:29

Ah - looks like Robert has explained it properly!

RobertDyck wrote:

SpaceNut wrote:
What I am trying to figure out is why the window to launch from earth is 2 yrs 7 weeks (779 days) when the mars sols are 668 (684 Earth days) in a Martian year.
Earth doesn't stay put, our plant orbits the Sun too. It's a matter of the two planets lining up with each other.
http://science.larouchepac.com/kepler/n … pter24.gif
Cosmic Train Schedule - assume Hohmann transfer orbit = 8.5 months. This table uses some simplifications for calculations, so dates are approximations.
This next schedule assumes also assumes a Hohmann transfer orbit. The lower chart shows solar cycle as a sin wave; higher means more solar radiation but less GCR, lower means lower solar radiation but more GCR. And the bars indicate likelihood of dust storms. They're perfect bars so that should tell you they're rough approximations.
http://web.mit.edu/12.000/www/finalpres … age157.gif

SpaceNut · 2016-01-02 21:15:12

Thanks RobertDyck for the planetary alignment info....

Tom Kalbfus · 2016-01-06 14:10:59

louis wrote:

Sorry I was forgetting about Mars's eccentricities (incidentally, I understand Mars's seasons aren't so pronounced either because of the axis wobble). However I don't think our "official" solstices/equinoxes line up exactly with orbital distance (there is a few days' difference I believe). So, I would prefer to stick with even divisions, even if they don't line up exactly with orbital distance.
On the launch window issue - that relates to Hohmann (?) Transfer Orbits, doesn't it? So, presumably it's some sort of interaction between Earth and Mars Orbits (and don't the launch windows vary significantly i.e. are you sure the window is always 779 days?).
SpaceNut wrote:
668 sols divided by 2 equals
334 sols for half a year then divided by 2 equals
167 sols for each season
But this is the Mars seasons time frame posted next:
Spring…7 months, Summer…6 months, Fall…5.3 months, and Winter…just over 4 months.
The way that scientists mark the time of Mars year is to use solar longitude, abbreviated Ls (read "ell sub ess"). Ls is 0° at the vernal equinox (beginning of northern spring), 90° at summer solstice, 180° at autumnal equinox, and 270° at winter solstice.

I don't know why they want to start the year at the beginning of spring rather than at the beginning of Winter as is traditional. That is like starting your day at sunrise rather than midnight. I think people would rather have Martian New Year's Day a week after Martian Christmas rather than three Martian months afterwards. These scientists that start their year in spring are no fun, and do they really expect us to give them three months Christmas Vacation?

louis wrote:

SpaceNut wrote:
Mars is at aphelion (its greatest distance from the Sun, 249 million kilometers, where it moves most slowly) at Ls = 70°, near the northern summer solstice, and at perihelion (least distance from the Sun, 207 million kilometers, where it moves fastest) at Ls = 250°, near the southern summer solstice. The Mars dust storm season begins just after perihelion at around Ls = 260°.
That said by looking at the numbers the only mark is a half year the lines up for the months totals on winter/spring or for summer/fall but its the length of the seasons that do not line up for the next interval of division of 2.
The orbit of mars is very egg shaped.
What I am trying to figure out is why the window to launch from earth is 2 yrs 7 weeks (779 days) when the mars sols are 668 (684 Earth days) in a Martian year.

Last edited by Tom Kalbfus (2016-01-06 14:12:14)

Terraformer · 2016-01-06 17:01:31

Why would you start your year at winter? I know we do - though we haven't always done so - but it means starting at the "death" stage of the birth-death-rebirth cycle, rather than the "rebirth" stage (spring).

louis · 2016-01-07 06:06:55

The Christian Church tried to make Easter the beginning of the year, but failed under the weight of pagan tradition and the inconvenient fact that the Easter date varies according to lunar cycles.

The "deep midwinter" is actually not a bad starting point - as it is when the seasonal trend changes, when days start to become longer. So it is the small beginning of rebirth.

Terraformer wrote:

Why would you start your year at winter? I know we do - though we haven't always done so - but it means starting at the "death" stage of the birth-death-rebirth cycle, rather than the "rebirth" stage (spring).

RobertDyck · 2016-01-07 13:24:26

Spring used to be the beginning of the year. April 1st was the start of the new year. Some king or emperor changed it to January 1st. I don't know which one. And they were very cruel back then; to enforce the change anyone who celebrated the old date for New Year would be executed. So "April Fool" was a way to trick someone into saying "Happy New Year". Once your victim said that, the king's guards would arrest that individual and kill him.

::Edit:: I wonder if that was part of the change to Roman rule, when Rome conquered Europe?

Last edited by RobertDyck (2016-01-07 13:26:06)

louis · 2016-01-07 15:11:14

Wikipedia comes to the rescue again:

"During the Middle Ages in western Europe, while the Julian calendar was still in use, authorities moved New Year's Day variously, depending upon locale, to one of several other days, among them: 1 March, 25 March, Easter, 1 September, and 25 December. These New Year's Day changes generally reverted to using January 1 before or during the various local adoptions of the Gregorian calendar, beginning in 1582. The change from March 25 – Lady Day, one of the four quarter days – to January 1 took place in Scotland in 1600, before the ascension of James VI of Scotland to the throne of England in 1603 and well before the formation of the Kingdom of Great Britain in 1707. In England and Wales (and in all British dominions, including Britain's American colonies), 1751 began on March 25 and lasted 282 days, and 1752 began on January 1.[2] For more information about the changeover from the Julian calendar to the Gregorian calendar and the effect on the dating of historical events etc., see Old Style and New Style dates."

[BTW - the Romans had a number of candidates for New Year which had their time in the Sun...and your story about the origin of April Fools Day must have been told you on 1st April!]

RobertDyck wrote:

Spring used to be the beginning of the year. April 1st was the start of the new year. Some king or emperor changed it to January 1st. I don't know which one. And they were very cruel back then; to enforce the change anyone who celebrated the old date for New Year would be executed. So "April Fool" was a way to trick someone into saying "Happy New Year". Once your victim said that, the king's guards would arrest that individual and kill him.
::Edit:: I wonder if that was part of the change to Roman rule, when Rome conquered Europe?

RobertDyck · 2016-01-07 17:00:05

louis wrote:

and your story about the origin of April Fools Day must have been told you on 1st April!

By my father, when I was a child.

Tom Kalbfus · 2016-01-08 10:57:44

Terraformer wrote:

Why would you start your year at winter? I know we do - though we haven't always done so - but it means starting at the "death" stage of the birth-death-rebirth cycle, rather than the "rebirth" stage (spring).

Because it minimizes the changes colonists would have to adapt to after relocating to Mars.
Mars, like the Earth has four seasons, and each of those four seasons has 3 months associated with it. For winter it is the tail end of December, January, February, and the beginning of March. For Spring we have the tail end of March, April, May, and the beginning of June. For Summer, its the end of June, July, August, and the beginning of September, and for Autumn we have the end of September, October, November, and the beginning of December. We can adjust this for Mars by making those months longer. People would look at a Martian calendar and know what time of the year is, without having to learn new names for months. People like to keep what they are used to, if it is not broken. To give you a counter example, during the French Revolution, a new metric time standard was proposed and a new calendar with new names of the months, 10 day weeks and 30 day months, with the remaining 5 or 6 days as loose days at the end of the year. This calendar was so different, that nobody liked it and it was dropped. The old Gregorian Calendar worked fine for most people, and they saw no reason to adopt the French Revolutionary Calendar just because they overthrew their king.

louis · 2016-01-08 19:57:31

I can understand how, as someone who also lives well to the north on the planet, you end up ignoring how many people - in the billions - live pretty close to the equator and so don't really experience huge seasonal changes during the year. We need to be aware of that. From a psychological point of view, equatorial people would probably be happy with a never-ending calendar that just went on and on (i.e. so you just proceed from Day 1 to Day 194406837087634087, rather than being cyclical). That's an interesting issue, I need to research...do equatorial peoples on Earth really have a calendar year and, if not, what sort of intervals, if any, do they observe?

The historical evidence suggests that people adapted pretty well to the French Revolutionary calendar in terms of months and years. It was the metric time they didn't like or want.

However, I think we are in general agreement it is a good idea to link the Mars calendar to the Mars seasons.

Tom Kalbfus wrote:

Terraformer wrote:
Why would you start your year at winter? I know we do - though we haven't always done so - but it means starting at the "death" stage of the birth-death-rebirth cycle, rather than the "rebirth" stage (spring).
Because it minimizes the changes colonists would have to adapt to after relocating to Mars.
Mars, like the Earth has four seasons, and each of those four seasons has 3 months associated with it. For winter it is the tail end of December, January, February, and the beginning of March. For Spring we have the tail end of March, April, May, and the beginning of June. For Summer, its the end of June, July, August, and the beginning of September, and for Autumn we have the end of September, October, November, and the beginning of December. We can adjust this for Mars by making those months longer. People would look at a Martian calendar and know what time of the year is, without having to learn new names for months. People like to keep what they are used to, if it is not broken. To give you a counter example, during the French Revolution, a new metric time standard was proposed and a new calendar with new names of the months, 10 day weeks and 30 day months, with the remaining 5 or 6 days as loose days at the end of the year. This calendar was so different, that nobody liked it and it was dropped. The old Gregorian Calendar worked fine for most people, and they saw no reason to adopt the French Revolutionary Calendar just because they overthrew their king.

SpaceNut · 2016-01-08 21:13:51

monsoons, huricanes, cyclones, tornado ect.....and if you are not in those the weather is dry forever......

So we will do a Mars version of a julian day calendar (1,2,3,4...668 then starting back at 1) with no day names or months with the martian people creating there own holidays for what they feel are the important things in life.....

louis · 2016-01-09 19:58:23

I favour four seasons of 167 sols, comprising 16 periods of ten sols (with those 16 periods further sub-divided into quarters of 4 x 10 sols) and a festival period of 7 days. The ten sol periods would be the equivalent of our weeks.

So each sol year would comprise 16 quarters (4 quarters for each of the four seasons), and four festival periods.

The idea would be that on Mars we have very well defined seasons (on Earth, seasonal definitions vary depending on calendar definitions, orbital definitions, and weather professionals definitions, to name a few).

I think the creation of non-religious Mars festival periods is important as well for cultural unity.

SpaceNut wrote:

monsoons, huricanes, cyclones, tornado ect.....and if you are not in those the weather is dry forever......
So we will do a Mars version of a julian day calendar (1,2,3,4...668 then starting back at 1) with no day names or months with the martian people creating there own holidays for what they feel are the important things in life.....

Tom Kalbfus · 2016-01-10 11:26:00

louis wrote:

I can understand how, as someone who also lives well to the north on the planet, you end up ignoring how many people - in the billions - live pretty close to the equator and so don't really experience huge seasonal changes during the year. We need to be aware of that. From a psychological point of view, equatorial people would probably be happy with a never-ending calendar that just went on and on (i.e. so you just proceed from Day 1 to Day 194406837087634087, rather than being cyclical). That's an interesting issue, I need to research...do equatorial peoples on Earth really have a calendar year and, if not, what sort of intervals, if any, do they observe?
The historical evidence suggests that people adapted pretty well to the French Revolutionary calendar in terms of months and years. It was the metric time they didn't like or want.
However, I think we are in general agreement it is a good idea to link the Mars calendar to the Mars seasons.
Tom Kalbfus wrote:
Terraformer wrote:
Why would you start your year at winter? I know we do - though we haven't always done so - but it means starting at the "death" stage of the birth-death-rebirth cycle, rather than the "rebirth" stage (spring).
Because it minimizes the changes colonists would have to adapt to after relocating to Mars.
Mars, like the Earth has four seasons, and each of those four seasons has 3 months associated with it. For winter it is the tail end of December, January, February, and the beginning of March. For Spring we have the tail end of March, April, May, and the beginning of June. For Summer, its the end of June, July, August, and the beginning of September, and for Autumn we have the end of September, October, November, and the beginning of December. We can adjust this for Mars by making those months longer. People would look at a Martian calendar and know what time of the year is, without having to learn new names for months. People like to keep what they are used to, if it is not broken. To give you a counter example, during the French Revolution, a new metric time standard was proposed and a new calendar with new names of the months, 10 day weeks and 30 day months, with the remaining 5 or 6 days as loose days at the end of the year. This calendar was so different, that nobody liked it and it was dropped. The old Gregorian Calendar worked fine for most people, and they saw no reason to adopt the French Revolutionary Calendar just because they overthrew their king.

Speaking of metric time, I'd say we use mks seconds in our Martian clocks, but use Mars Minutes and hours. You see the minute and the hour are not metric time units as they are not multiples of ten in seconds. Since a Sol is 1.025957 times an earth day, a Mars minute is 1.025957 times an Earth minute, and when multiplied by 60 this makes a Mars minute 61.55742 seconds long, and we'll just leave it at that. The Mars minute is still 1/60th of a Mars Hour, and a Mars Hour is 1/24 of a Mars Sol. Seconds are metric units so we leave those along and don't create a Martian counterpart to them. If you want you can have dekaseconds (das) hectoseconds (hs), and kiloseconds (ks).

Tom Kalbfus · 2016-01-10 11:28:43

SpaceNut wrote:

monsoons, huricanes, cyclones, tornado ect.....and if you are not in those the weather is dry forever......
So we will do a Mars version of a julian day calendar (1,2,3,4...668 then starting back at 1) with no day names or months with the martian people creating there own holidays for what they feel are the important things in life.....

I think giving the months names, just like we name the seasons would give the place a homey touch, basically we divide up the year into 12 seasons and call them "months", the hottest would by July, and the coldest would be January in the Northern Hemisphere. I think when the colonies become more established not all or even most of the residence would be scientists that like to assign numbers instead of proper names to everything.

Last edited by Tom Kalbfus (2016-01-10 11:30:26)

Tom Kalbfus · 2016-10-21 23:37:36

This is based on the Darrian Calendar:
https://en.wikipedia.org/wiki/Darian_calendar
Here is the first month of my Mars Calendar, this one is designed to hang on the wall and above is a picture of Mars or about Mars.

Tom Kalbfus · 2016-10-21 23:52:52

On the other hand, why not use Month names and double their size

This is the Martian Month of March, the spring Equinox is set on March 20, same as on Earth Calendars. Having more days provides more balance between Month and picture. What do you think? This is also closer to the calendar Zubrin proposed, but I prefer not to name the months after astrological signs.

louis · 2016-10-24 19:27:50

I'm not fond of Latin names for the days or months.

I think we should look to the exploration of Mars and Mars pioneers - so Schiaperelli (spelling?), Musk, Mariner, Viking, Opportunity, Spirit...let's make use of all those names.

Tom Kalbfus · 2016-10-25 07:42:18

But we associate March with the beginning of spring. Mars has seasons, Earth has seasons, each part of the Earth year has its analog for Mars, so why not use 12 months but make them longer? There are a lot of cultural reasons for this. We are familiar with the month names of January through December, so why not use them for Mars as well? And since Earth Mars month is longer than its equivalent Earth month, we know where to put all the traditional holidays, in the first half of each Mars Month. Christmas would be o December 25th, and then you have half a Mars Month left before you celebrate New Years Day!

louis · 2016-10-25 13:41:02

As above, I still favour four seasons of 167 sols, comprising 16 periods of ten sols (with those 16 periods further sub-divided into quarters of 4 x 10 sols) and a festival period of 7 days. The ten sol periods would be the equivalent of our weeks.

So each sol year would comprise 16 quarters (4 quarters for each of the four seasons), and four festival periods.

Tom Kalbfus wrote:

But we associate March with the beginning of spring. Mars has seasons, Earth has seasons, each part of the Earth year has its analog for Mars, so why not use 12 months but make them longer? There are a lot of cultural reasons for this. We are familiar with the month names of January through December, so why not use them for Mars as well? And since Earth Mars month is longer than its equivalent Earth month, we know where to put all the traditional holidays, in the first half of each Mars Month. Christmas would be o December 25th, and then you have half a Mars Month left before you celebrate New Years Day!

Tom Kalbfus · 2016-10-25 14:28:38

louis wrote:

As above, I still favour four seasons of 167 sols, comprising 16 periods of ten sols (with those 16 periods further sub-divided into quarters of 4 x 10 sols) and a festival period of 7 days. The ten sol periods would be the equivalent of our weeks.
So each sol year would comprise 16 quarters (4 quarters for each of the four seasons), and four festival periods.

Tom Kalbfus wrote:
But we associate March with the beginning of spring. Mars has seasons, Earth has seasons, each part of the Earth year has its analog for Mars, so why not use 12 months but make them longer? There are a lot of cultural reasons for this. We are familiar with the month names of January through December, so why not use them for Mars as well? And since Earth Mars month is longer than its equivalent Earth month, we know where to put all the traditional holidays, in the first half of each Mars Month. Christmas would be o December 25th, and then you have half a Mars Month left before you celebrate New Years Day!

Okay, on what date would Martian colonists pop their Champaign corks and celebrate a New Year? When would they celebrate Christmas, Easter, Valentines Day, Halloween, Saint Patrick's Day?

New Mars Forums

Announcement

#51 2016-01-01 14:52:02

Re: Martian Calender - I have created a martian calender...

#52 2016-01-01 19:36:52

Re: Martian Calender - I have created a martian calender...

#53 2016-01-01 22:19:56

Re: Martian Calender - I have created a martian calender...

#54 2016-01-02 00:45:57

Re: Martian Calender - I have created a martian calender...

#55 2016-01-02 18:19:14

Re: Martian Calender - I have created a martian calender...

#56 2016-01-02 18:20:29

Re: Martian Calender - I have created a martian calender...

#57 2016-01-02 21:15:12

Re: Martian Calender - I have created a martian calender...

#58 2016-01-06 14:10:59

Re: Martian Calender - I have created a martian calender...

#59 2016-01-06 17:01:31

Re: Martian Calender - I have created a martian calender...

#60 2016-01-07 06:06:55

Re: Martian Calender - I have created a martian calender...

#61 2016-01-07 13:24:26

Re: Martian Calender - I have created a martian calender...

#62 2016-01-07 15:11:14

Re: Martian Calender - I have created a martian calender...

#63 2016-01-07 17:00:05

Re: Martian Calender - I have created a martian calender...

#64 2016-01-08 10:57:44

Re: Martian Calender - I have created a martian calender...

#65 2016-01-08 19:57:31

Re: Martian Calender - I have created a martian calender...

#66 2016-01-08 21:13:51

Re: Martian Calender - I have created a martian calender...

#67 2016-01-09 19:58:23

Re: Martian Calender - I have created a martian calender...

#68 2016-01-10 11:26:00

Re: Martian Calender - I have created a martian calender...

#69 2016-01-10 11:28:43

Re: Martian Calender - I have created a martian calender...

#70 2016-10-21 23:37:36

Re: Martian Calender - I have created a martian calender...

#71 2016-10-21 23:52:52

Re: Martian Calender - I have created a martian calender...

#72 2016-10-24 19:27:50

Re: Martian Calender - I have created a martian calender...

#73 2016-10-25 07:42:18

Re: Martian Calender - I have created a martian calender...

#74 2016-10-25 13:41:02

Re: Martian Calender - I have created a martian calender...

#75 2016-10-25 14:28:38

Re: Martian Calender - I have created a martian calender...

Board footer