Author Topic: Mars Timekeeping System  (Read 15626 times)

Online Stan-1967

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Re: Mars Timekeeping System
« Reply #20 on: 11/04/2016 06:17 AM »
Those living on Mars would want a sunlight oriented system for sols like we have on Earth.  I think it's a bad idea to alter the second proportionately as some elsewhere have suggested.  Although not noticed by Mars residents it could complicate engineering calculations and be a source of error.

My radical Mars quirky solution is to use normal Earth hours minutes and seconds but at midnight when all but the night shift and those wild & crazy late night Mars party animals are asleep, have the clocks go to Red Time where the extra 39 minutes 35.244 seconds are added and counted down before resuming at say 12:01.  Mars sols are preserved.  Everyone in the inner solar system is using standard seconds, etc.  And a party time is enshrined in unique Mars culture.

How does that work for multiple time zones?  And for shift work?

I think it could still work fine.  It would operate like "overtime" in any familiar sporting event you want to compare against.  The final 24th  hour of the day would not roll over at 60 minutes past the hour, but keep ticking away to 24h 99min &  35.244 seconds then it's becomes 1am.  This would be the case in every time zone. 

We accept some randomness in our definitions of time periods here on earth.   Every four years we have a leap year, where we alter the definition of a year from 365 days to 366 days.   Martians will do something like this every night.  On Mars, an hour is equal to 60 minutes, with the exception of the last hour of the day, which is equal to 99 minutes & 35.244 seconds.  If that's too messy, just call it any name your want, overtime, Red Time, purge time, etc., but define it as 39 minutes and 35.244 seconds, & don't roll over the clock to the next day until that time period is expired.

As for shift workers, just pay them by the minute.  I'm sure the unionized ones will find a way to slack off for that hanging chad of 35.244 seconds to keep the math simple.



Online Bynaus

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Re: Mars Timekeeping System
« Reply #21 on: 11/04/2016 08:04 AM »
I don't think time-keeping on Mars would change much, certainly not initally. People would still feel comfortable counting in minutes (60 s each), hours (60 min each), days (of 24 hours and 38 minutes each) and weeks (7 days each). Machines will still expect seconds to be SI-seconds.

So I think nothing will really change much, except for the fact that there would be 668.6 sols in a martian year (which is an important cycle especially for a solar-powered colony, as this is the time horizon / cycle length over which energy storage and crop production has to be managed). It would feel most natural to just drop the month system (no "Moon" anyway...) and subdivide the year in weeks (of 7 days) instead of months, so you would simply have 95.5 weeks per (martian) year.

The half-week could be used for festivities, so that each year could start on the same day of the week. Then, your birth-date on Mars could simply be, say, Tuesday 49th, 23, meaning Tuesday of the 49th week in the 23rd year after the first landing.

Offline Jim

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Re: Mars Timekeeping System
« Reply #22 on: 11/04/2016 10:05 AM »

I think it could still work fine.  It would operate like "overtime" in any familiar sporting event you want to compare against.  The final 24th  hour of the day would not roll over at 60 minutes past the hour, but keep ticking away to 24h 99min &  35.244 seconds then it's becomes 1am.  This would be the case in every time zone. 

We accept some randomness in our definitions of time periods here on earth.   Every four years we have a leap year, where we alter the definition of a year from 365 days to 366 days.   Martians will do something like this every night.  On Mars, an hour is equal to 60 minutes, with the exception of the last hour of the day, which is equal to 99 minutes & 35.244 seconds.  If that's too messy, just call it any name your want, overtime, Red Time, purge time, etc., but define it as 39 minutes and 35.244 seconds, & don't roll over the clock to the next day until that time period is expired.
.


No,  it wouldn't.  It is 11pm and a person wants to have a telecon with groups in 3 different time zone in 200 minutes.   What time would that be in each time zone?
« Last Edit: 11/04/2016 10:05 AM by Jim »

Offline Jim

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Re: Mars Timekeeping System
« Reply #23 on: 11/04/2016 10:09 AM »

I think it could still work fine.  It would operate like "overtime" in any familiar sporting event you want to compare against.  The final 24th  hour of the day would not roll over at 60 minutes past the hour, but keep ticking away to 24h 99min &  35.244 seconds then it's becomes 1am.  This would be the case in every time zone. 


That is the wrong way to do, if you are going to have red time.   The last hour would be 23h 99min &  35.244 and then it becomes 0000h
« Last Edit: 11/04/2016 10:11 AM by Jim »

Online rsdavis9

Re: Mars Timekeeping System
« Reply #24 on: 11/04/2016 11:05 AM »
I think mars sols are good.
Keep "normal" hours, minutes, seconds.
martian years of martian sols.

Get rid of timezones. We only have timezones because we use to use the sun as our clock.
People get used to a time being a location specific sun condition. So it doesn't matter what it is as long as it stays the same day after day. So time of day starts for the prime mars meridian having the mean sun passing it. It ends when the mean sun makes 360 degrees of rotation. Just because mars doesn't have exactly 86400 seconds in it shouldn't matter.

So without timezones. Helas basin colonists would get used to 7:35 being sunrise. and 18:37 being sunset. Of course seasonal variations change that somewhat. Another location would have 23:53 as sunrise and 12:01 (the next day) as sunset.
bob

Offline Jim

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Re: Mars Timekeeping System
« Reply #25 on: 11/04/2016 11:21 AM »

So without timezones. Helas basin colonists would get used to 7:35 being sunrise. and 18:37 being sunset. Of course seasonal variations change that somewhat. Another location would have 23:53 as sunrise and 12:01 (the next day) as sunset.


That is impractical.  So when one travels to a different location, how would they know when the start of the day is?  When does work start or shops open?

Online rsdavis9

Re: Mars Timekeeping System
« Reply #26 on: 11/04/2016 11:31 AM »

So without timezones. Helas basin colonists would get used to 7:35 being sunrise. and 18:37 being sunset. Of course seasonal variations change that somewhat. Another location would have 23:53 as sunrise and 12:01 (the next day) as sunset.


That is impractical.  So when one travels to a different location, how would they know when the start of the day is?  When does work start or shops open?

Everytime I travel on earth work and shops change. So do the open/start times. So when doing a big move you get used to different times.
bob

Offline Jim

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Re: Mars Timekeeping System
« Reply #27 on: 11/04/2016 11:42 AM »


Everytime I travel on earth work and shops change. So do the open/start times. So when doing a big move you get used to different times.


You at least know it is 9 or 10am when they open

Online rsdavis9

Re: Mars Timekeeping System
« Reply #28 on: 11/04/2016 11:51 AM »
When I travel to california customer service reps start work at 7am or earlier so as to better serve east coast customers. When I go to work in the east coast work starts 8 or 9am.

Personally I hate am and pm. Gotten confused too many times. Timezones fall into the same class for me. Mass confusion about when something happens. I see questions on this forum numerous times saying that EST? what time is that in CET.

Ugh!
UTC is so much easier.
I have a good friend that everytime he traveled he would keep his watch set to EST(where he lives) and would just convert while away from home.

The last time I got bit by AM/PM was when I had a flight out of orlando back to boston. I printed out the boarding passes and never noticed the departure time was 7PM. So I got up early to get on a flight for what I thought was 7AM. Luckily the airlines let me get on a earlier flight with no fee instead of making me wait in the airport for 12 hours!

bob

Offline philw1776

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Re: Mars Timekeeping System
« Reply #29 on: 11/04/2016 11:54 AM »
Those living on Mars would want a sunlight oriented system for sols like we have on Earth.  I think it's a bad idea to alter the second proportionately as some elsewhere have suggested.  Although not noticed by Mars residents it could complicate engineering calculations and be a source of error.

My radical Mars quirky solution is to use normal Earth hours minutes and seconds but at midnight when all but the night shift and those wild & crazy late night Mars party animals are asleep, have the clocks go to Red Time where the extra 39 minutes 35.244 seconds are added and counted down before resuming at say 12:01.  Mars sols are preserved.  Everyone in the inner solar system is using standard seconds, etc.  And a party time is enshrined in unique Mars culture.

How does that work for multiple time zones?  And for shift work?

I may not understand the question, but as on Earth there would be multiple time zones, each using the same 24 Hr 39 minute system.

If you're on night shift, your digital clocks simply display Red Time for 39 minutes after 12 AM.  If the question is if they're paid per hour, do they get time and a half for those minutes, I dunno!
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Offline baldusi

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Re: Mars Timekeeping System
« Reply #30 on: 11/04/2016 02:20 PM »
Well, one interesting fact about Mars orbit is that it is more elliptical than Earth's. So, seasons have different lengths (194 to 142 max min). This also means that the difference between sideral and solar day varies with the year.
I'm wondering if this could be used to have "built in" time differences (like having certain days with 25hrs and some with 24hs) to keep the year right but both keep the martian year and the solar year closer to the solar cycle.

Online rsdavis9

Re: Mars Timekeeping System
« Reply #31 on: 11/04/2016 02:24 PM »
Well, one interesting fact about Mars orbit is that it is more elliptical than Earth's. So, seasons have different lengths (194 to 142 max min). This also means that the difference between sideral and solar day varies with the year.
I'm wondering if this could be used to have "built in" time differences (like having certain days with 25hrs and some with 24hs) to keep the year right but both keep the martian year and the solar year closer to the solar cycle.

Thats just the difference between mean sun and actual sun. The equation of time is what it is called. On earth it is 16min. On mars it is larger.
bob

Offline baldusi

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Re: Mars Timekeeping System
« Reply #32 on: 11/04/2016 03:23 PM »
Well, one interesting fact about Mars orbit is that it is more elliptical than Earth's. So, seasons have different lengths (194 to 142 max min). This also means that the difference between sideral and solar day varies with the year.
I'm wondering if this could be used to have "built in" time differences (like having certain days with 25hrs and some with 24hs) to keep the year right but both keep the martian year and the solar year closer to the solar cycle.

Thats just the difference between mean sun and actual sun. The equation of time is what it is called. On earth it is 16min. On mars it is larger.
You are assuming a constant radial velocity, which would keep the precession constant. On more elliptical orbits than Earth, the rate varies through the year, the difference is significant. This means days which are "longer" and "shorter". Not in the daylight sense but on the total length of the cycle (e.g. dawn to dawn).
May be that variance can be used to introduce leap hours to keep a more logical time system. I don't like to use prime numbers for hours, minutes and seconds.


Offline philw1776

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Re: Mars Timekeeping System
« Reply #34 on: 11/04/2016 03:40 PM »
https://en.wikipedia.org/wiki/Equation_of_time#Explanations_for_the_major_components_of_the_equation_of_time

https://en.wikipedia.org/wiki/Analemma#/media/File:Mars_analemma.GIF

so the equation of time is about +- and hour.

Maybe the Martians will invent a system to deal with this.  Call it something, say like "Daylight Savings Time"  or somesuch? :)
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Offline ThereIWas3

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Re: Mars Timekeeping System
« Reply #35 on: 11/04/2016 04:37 PM »
I liked Jim's idea of stretching the last hour of the day rather than inserting a time-slip.  But then I realized that if this is combined with time zones it gets confusing again, as each time zone would be stretching an hour at a different global time.

How about say each hour consists of 61 minutes and 39 seconds?  24 such hours add up to the correct total, all hours are the same length everywhere on Mars, your computerized wristwatch does the math, and time zones are possible.   You would hardly notice the difference for most human activities.   But if you are timing a critical process, navigation, rocket launches, better just use units of seconds, just like the SI system is supposed to.   I remember in the "Orbiter" space simulation program, all timestamps are in seconds, so you get things like "Launch will be at 57,322.7 seconds"

Alternately, define the 'minute' to be a tiny bit longer, rather than the hour.  It works out the same.
« Last Edit: 11/04/2016 04:40 PM by ThereIWas3 »
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Online Robotbeat

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Re: Mars Timekeeping System
« Reply #36 on: 11/04/2016 05:47 PM »
A mini party during the Red Time each night!
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Offline MP99

Re: Mars Timekeeping System
« Reply #37 on: 11/04/2016 06:54 PM »
How about a standard day of 24:40, then about every 25th day is 24:30 long?

Clocks would never get more than five minutes out of sync with the daylight cycle.

It does mean that on transition day, the hours in some time zones would be 10 minutes adrift until they also hit midnight.

That might also make for a natural "month" analogue - the last day of the "month" would be shorter. This would also make it easier for people to remember about the "leap" minutes. If today is the first, then westerly timezones which haven't yet reached midnight are 10 minutes behind. If tomorrow is the first, then easterly timezones which are past midnight are 10 mins ahead.

Unfortunately, months wouldn't fit into a year - much as Lunar months don't on earth.

Cheers, Martin

PS programmers would curse this scheme - makes for some nasty timezone and time difference calculations, with various conditionals.

Edit:mixed up east and west.
« Last Edit: 11/04/2016 06:59 PM by MP99 »

Offline mrhuggy

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Re: Mars Timekeeping System
« Reply #38 on: 11/04/2016 07:50 PM »
I actually did some work on this about 20+ years ago.

1 Martian Second = 1.025956010 Earth Second

60 Msec Per Minutes
60 Minutes per Hour
24 Hours per Day

Making the second slightly longer keeps things usable.

The Year would be split into 98  7 day weeks. This would leave you with 1 day which would be new years day.

So you would have a time looking like 12:28 Monday 89 2025
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Offline Paul451

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Re: Mars Timekeeping System
« Reply #39 on: 11/04/2016 11:43 PM »
I find it bizarre that people are trying to force some equivalent of weeks and months into the Martian year. Or even time-zones.

These are not medieval tenant farmers. They are highly educated, technologically equipped, first-world space colonists.

"How will you know when the stores open?" {sigh} Seriously? It's the 21st freakin' century.

--

It's worth noting that the calendar year on Earth came long after the development of weeks/months/seasons. Lunar calendars were more common initially (hence months). And every region generally used their own incompatible calendars. (Even seasons weren't standard.)

Likewise, time "zones" didn't exist, in any meaningful sense. There was only ever the time where you were, based on local noon. Ten miles down the road, the time would be different.

Every village kept its own time. Every ship used its local time, not the local time-zone. That is, they calculated local noon, they did not work out which 1/24th time-zone they were in. Railway schedules seem to have standardised regions into single "time-zones", which then led to global standardisation. (For very low values of "standard", when you look at an actual map.)

China copes with a single time-zone instead of the 4 or 5 they should be using. Russia mostly ignores 4 of their 11 time zones. The US military generally uses a single "time-zone" (GMT) globally to make communication easier.  The trend has been to collectivise local times into zones, not to divide them. And much of the wonkiness of the time-zone map is because of regions pushing themselves into neighbouring time-zones for commercial reasons, trade and communications mattering more than keeping track of local noon.

--

So looking at how Martian settlement would evolve: There would the site of the first colony. Most secondary sites would be close enough to the colony that they would just use the same time. Missions (such as science stations) at significant distance would likewise use the same standard colony time for convenience and communication. Hence there'd be one standard time-zone for the entire planet (and one standard Earth-time (GMT) that they'd compare that to.)

By the time there are enough large secondary colonies far enough away from the primary colony for local-noon to differ by more than a couple of hours, the Standard Mars Time created by that first colony site would be culturally entrenched. Secondary time-zones are unlikely to then be adopted due to the perceived disadvantages they create. (I mean, think about the ridiculousness of the International Dateline. Australian and US readers are on different days.)

Similarly, it would be silly to divide the Martian year into weeks/months. There's no pre-existing tradition of a Mars calendar, it would just be a clumsy arbitrary system to memorise. The first colony would just count sols, and that would become the tradition.

In fact, I'm not even convinced they'd bother to use the Martian year for a calendar. Again, these aren't medieval farmers. Mostly they'd use keep counting in Earth-years. You could even use Earth weeks, mostly. Even counting sols, you'd only lose 3 "days" every 109 sols. Ie, during a 16 weeks cycle, you need to have three short weeks and that keeps you in approximate sync with the Earth calendar.

[And if you were going to use anything other than Earth years, it would more likely be based around the Earth-Mars synod, which will be the most important cycle to colonists for decades, and thus the most likely to become "traditional". Nearly 760 sols/780 days. And by the time you have a large enough Martian population for the majority to no longer care about transfer orbits, it would have long since become traditional. Synod 50 rather than Mars-Year 56.]

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