Intergalactic Time?

Why does dividing by 240 imply anything about how many months the mortgage is other than "longer than 240 repayment periods"?

A $400,000 mortgage in the real world at 6.5% APR for a 30 year loan would have a payment about 160th the principal of the loan. Does that mean the real world has 320 months over the course of 30 years?
One is a game and the other reality. Games tend to have numbers that make obvious patterns, the real world not so much.
 
Anything in the rules say that the Imperial Calendar is NOT 364 days plus a New Year's Day named Holiday? Anything say that the Imperial Calendar is NOT divided into 7 day weeks, with days named Wonday, Twoday, Thriday, Forday, Fiday, Sixday, and Senday?

If the months are 12 of 30 days, then what does the Imperial Calendar do with the remaining extraneous four days other than Holiday? What is the Canon answer?

And annual maintenance is mandated, independent of monthly maintenance, going all the way back to Classic Traveller.
The canon calendar is 13 months of 28 days plus a single Holiday between the years. What does that have to do with mortgage payments only being required 12 times a year when it is explicit in the rules that they're monthly?

Annual maintenance at a shipyard is required, but what says it takes an entire month to do?
 
And annual maintenance is mandated, independent of monthly maintenance, going all the way back to Classic Traveller.
Was mandated in CT. Monthly I don't think was.

Now GDW (1983) traveller did say that it was 480 monthly payments for 40 years and no mention of a free month yearly that I saw.

CT traveller had the annual maintenance be 2 weeks (1977 Book 02 Starships) no mention I could find about any free month off the mortgage.
The canon calendar is 13 months of 28 days plus a single Holiday between the years. What does that have to do with mortgage payments only being required 12 times a year when it is explicit in the rules that they're monthly?

Annual maintenance at a shipyard is required, but what says it takes an entire month to do?
Where in canon does it say the year is 13 months + a holiday? Where does it say maintenance must be at a shipyard?

Those deep space missions planning decades carry along a shipyard big enough for the largest ship?

As far as I can see maintenance can be done underway if you have the parts or where ever your ship sets down again given the parts. Serious repairs and overhauls, sure they need a shipyard of some sort but not the month to month normal wear and tear maintenance. I don't see anything in current rules about a yearly shipyard done maintenance.
 
Where in canon does it say the year is 13 months + a holiday? Where does it say maintenance must be at a shipyard?

Those deep space missions planning decades carry along a shipyard big enough for the largest ship?

As far as I can see maintenance can be done underway if you have the parts or where ever your ship sets down again given the parts. Serious repairs and overhauls, sure they need a shipyard of some sort but not the month to month normal wear and tear maintenance. I don't see anything in current rules about a yearly shipyard done maintenance.

Once a year maintenance should be done at a shipyard. Core rulebook, page 154, 'Repairs and Maintenance'.

A ship needs maintenance, which costs 0.1% of the total purchase price of the ship per year. Maintenance should be carried out every Maintenance Period (divide the year’s maintenance cost by 12 to find the Maintenance Period cost. Once per year this should be performed at a shipyard

Long-duration ships can be built to require less maintenance, but it's expensive. Those rules are in the Deepnight Revelation campaign set if I remember right.

And yes, I see the contradiction with the yearly maintenance cost being divided by 12 to find the maintenance period cost, but maintenance periods are explicitly 4 weeks long (the previous page); the 12 is clearly an error or not different enough to matter.

The Imperial Calendar is 13 months + a holiday. Third Imperium, page 3, 'Conventions':

Each of the Major Races has its own dating system but this book uses that of Humaniti, specifically the Imperial Calendar. The Imperium measures time in years, which consist of 365 days of 24 hours each. The first day of the year is called Holiday and the remainder of the year is divided into seven-day weeks, whose days are called Wonday, Tuday, Thirday, Forday, Fiday, Sixday and Senday. The current year is 1105, the 1,105th year of the Third Imperium. Historical records referring to events that occurred before the Imperium was founded are shown as negative numbers. For example, Cleon I, the first Emperor of the Third Imperium, was born in the year -57.
 
The canon calendar is 13 months of 28 days plus a single Holiday between the years. What does that have to do with mortgage payments only being required 12 times a year when it is explicit in the rules that they're monthly?

Annual maintenance at a shipyard is required, but what says it takes an entire month to do?
Who said it takes a month?

A week in jump to get to get to the system .

A week or so to Manoeuvre to the main world,

Two weeks in system for inspection and maintenance (and time for crew to take port liberty and take advantage of down time).

A week either travelling outsystem, or remaining in system to drum up business afterwards. Now we have exhausted our month.
 
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If it takes a week to travel in (or out)-system, that's an *extremely* slow spacecraft or an extremely odd star system.

Either way, you're making stuff up that's not supported by anything in the books. That's fine, that's a house rule, but you shouldn't pretend it is anything besides that.
 
Once a year maintenance should be done at a shipyard. Core rulebook, page 154, 'Repairs and Maintenance'.
Thanks, I didn't remember that one.

That maintenance however is not a month it is just one of the 12 "monthly" periods of maintenance SHOULD not MUST be done in a shipyard. Allows for years away from a shipyard so long as you have parts and avoid serious damage (battles, crashes, sabotage etc). Could end up just a few hours or maybe a couple of days hooked up to a diagnostics computer doing some tuning up and minor component swaps and inventory filling.

I've been looking up what a "month" is and it seems to be adhoc, whatever is wanted locally around 4 weeks in time. Now the banks could be strict on you pay your mortgage each of the first 12 4 week cycles in the year, the "13" isn't a skipped payment it is just that you are up to date for the whole year. It also allows the payments of the mortgage to be flexible within the year without ever being called behind so long as no more than 1 is delayed into that 13th cycle and then for good reason.

Learn new things all the time.
 
Thanks, I didn't remember that one.

That maintenance however is not a month it is just one of the 12 "monthly" periods of maintenance SHOULD not MUST be done in a shipyard. Allows for years away from a shipyard so long as you have parts and avoid serious damage (battles, crashes, sabotage etc). Could end up just a few hours or maybe a couple of days hooked up to a diagnostics computer doing some tuning up and minor component swaps and inventory filling.

I've been looking up what a "month" is and it seems to be adhoc, whatever is wanted locally around 4 weeks in time. Now the banks could be strict on you pay your mortgage each of the first 12 4 week cycles in the year, the "13" isn't a skipped payment it is just that you are up to date for the whole year. It also allows the payments of the mortgage to be flexible within the year without ever being called behind so long as no more than 1 is delayed into that 13th cycle and then for good reason.

Learn new things all the time.

Maintenance is not required once per month. It is required once per maintenance period, which is explicitly defined as 4 weeks, and it is 'required' in the sense that if you don't do it you are subject to the rules for poor maintenance (rolling 2D on every following Maintenance Period with a DM equal to the number of Maintenance Periods skipped; on an 8+, the ship suffers a critical hit and you roll 2D on a table and apply the effects, which can include things like "the power plant starts irradiating the crew").
 
If it takes a week to travel in (or out)-system, that's an *extremely* slow spacecraft or an extremely odd star system.

Either way, you're making stuff up that's not supported by anything in the books. That's fine, that's a house rule, but you shouldn't pretend it is anything besides that.

What have I "made up"? First of all, what I noted above has been an inference drawn from the available data by the Traveller community for decades. *I* most certainly did NOT "make it up".

CT'77 Book 2:
STARSHIP PURCHASE
Bank financing is available to qualified individuals for the purchase of commer-
cial starships. After a down payment of 20% of the cash price of the starship is made,
the shipyard will begin construction of a specific vessel. Upon completion, the vessel
is delivered to the buyer, with the bank paying off the purchase price to the shipyard.
Because the bank now holds title to the ship, the price must be paid off in a series of
monthly payments to it. Standard terms involve the payment of 1/240th of the cash
price each month for 480 months. In effect, interest and bank financing cost a simple
120% of the final cost of the ship, and the total financed price equals 220% of the
cash purchase price. The loan is paid off over a period of 40 years.
In addition, the bank will insist that the purchaser submit an economic plan detailing
the projected activity which will guarantee that monthly payments are made. Unless
a character has some form of guaranteed income (perhaps large royalties from some
property he owns), these conditions will generally rule out purchases (at least fi-
nanced purchases) of yachts, military vessels, or exploratory vessels.
3. Routine Maintenance. Annually, a starship should be given a complete over-
haul in order to insure that it is kept in good working order. Such maintenance costs
0.1% (1/1000th) of the cash price of the ship, and requires two weeks at a class A or B
starport. The owner must make provision for payment of the maintenance fee when
it comes due. Crew members generally take their vacation at this time, but must still
be paid. Provision should also be made for the expected loss of revenue while the
ship is out of service.

Given that the year is known to be 364+1 days comprised of 7 day weeks +1 day, how do you square this with 12 monthly payments per annum, or 13 payments per annum, based on the schedule above, and follow the promoted Imperial Calendar?

What is your canonical resolution? Or do you simply draw a logical inference and house rule it?
 
And has it ever occured to anyone that perhaps the loan repayment schedule is intentionally structured in such a way that by taking what would normally be the monthly rate for 13 monthly payments per annum and increasing that monthly rate so as to pay off that entire annual 13 month sum in only 12 payments, the annual maintenance period downtime is proactively accounted for?
 
What have I "made up"? First of all, what I noted above has been an inference drawn from the available data by the Traveller community for decades. *I* most certainly did NOT "make it up".

CT'77 Book 2:



Given that the year is known to be 364+1 days comprised of 7 day weeks +1 day, how do you square this with 12 monthly payments per annum, or 13 payments per annum, based on the schedule above, and follow the promoted Imperial Calendar?

What is your canonical resolution? Or do you simply draw a logical inference and house rule it?
I square it with "human error", just like the "4 weeks per maintenance period" and "divide yearly maintenance cost by 12 to get what you pay per maintenance period" rules in modern Traveller, which simply don't work when put together. Yea, that's a logical inference, but I'm also not pretending that rules as written and intended it's clear that banks only require you to pay twelve months out of a thirteen month year or that Capital clearly has exactly the same year and day cycle as Earth.
 
Where in canon does it say the year is 13 months + a holiday? Where does it say maintenance must be at a shipyard?



Three major dating systems are in use when referring to historical events: Terran, Vilani, and Imperial.
Terran dates center on a year about midway through the period of Vilani ascendance. After that date, years ascend, and are suffixed AD; before that date, years descend, and are suffixed BC. There is no year zero. Terran years have 365 days and are considered a standard for length of year. Years are further subdivided into months and weeks, although these divisions have fallen into disuse outside the Solomani Sphere.
Vilani dates count from the year of the establishment of the First (or Vilani) Imperium. Those before are suffixed PI (pre-Imperium), those after are suffixed VI (Vilani Imperium). There is no year zero. Vilani years are approximately 1.33 standard years in length. Vilani years are further divided into seasons, months, and weeks.
Imperial dates count from the year of the founding of the Third Imperium, specifying the year zero as a holiday year. Dates before that are negative; dates after that are positive, with the sign usually suppressed. Imperial dating uses a julian system for specifying days. Each day in the year i s consecutively numbered beginning with 001. Thus, in the year 1105, the first day of the year is 001-1105. Weeks of seven days and months of 28 days are used to refer to lengths of time, but rarely to establish dates.

The Traveller Book, Pg.152 - GDW (1982)


Three major dating systems are in use when referring to historical events: Terran, Vilani, and Imperial.
Terran dates center on a year about 4500 years before the founding of the Third Imperium. After that date, years ascend, and are suffixed AD; before that date, years descend, and are suffixed BC. There is no year zero.
Vilani dates count from the year of the establishment of the Pax Vilanica (using the Vilani year, which is equal to 1.33 standard years). Those before are suffixed PI (pre-Imperium); those after are suffixed VI (Vilani Imperium).
Imperial dates count from the year of the founding of the Third Imperium, specifying the year zero as a holiday year. Dates before that are negative, dates after that positive, with the sign usually suppressed. Imperial dating uses a Julian system for days. Each day in the year is consecutively numbered beginning with 001. Thus, in the year 1105, the first day of the year is 001-1105.
Zhodani dating is in olympiads (obviously a translation). Each olympiad is of three Zhodani years; each Zhodani year is 0.75 standard years, and an olympiad is 2.24 standard years. The first olympiad corresponds to -6730; 1106 corresponds to the 3498th olympiad.

Introductory Adventure: The Imperial Fringe, Pg.20 - GDW (1982)


Three major dating systems are in use when referring to historical events— Terran, Vilani, and Imperial. A fourth system (Zhodani olympiads) is of passing interest.
Terran dates center on a year about midway through the period of Vilani ascendance. After that date, years ascend, and are suffixed AD; before that date, years descend, and are suffixed BC. There is no year zero. Terran years have 365 days and are considered a standard for length of year. Years are further subdivided into months and weeks, although these divisions have fallen into disuse outside the Solomani Sphere.
Vilani Dates count from the year of the Establishment of the First (or Vilani) Imperium. Those before are suffixed PI (pre-lmperium), those after are suffixed VI (Vilani Imperium). There is no year zero. Vilani years are approximately 1.33 standard years in length. Vilani years are further divided into seasons, months, and weeks.
Imperial dates count from the year of the founding of the Third Imperium, specifying the year zero as a holiday year. Dates before that are negative, dates after that are positive, with the sign usually suppressed. Imperial dating uses a Julian system for specifying days. Each day in the year is consecutively numbered beginning with 001. Thus, in the year 1105, the first day of the year is 001-1105. Weeks of seven days and months of 28 days are used to refer to lengths of time, but rarely to establish dates.
Zhodani dating is counted in olympiads (obviously a translation). Each olympiad is of three Zhodani years; each zhodani year is .75 standard years. The first olympiad corresponds to 2209 BC. The dating system itself has been in more or less continuous use since then, with minor lapses due to war or temporary decline of ruling parties.
Supplement 8: Library Data (A-M), Pg.22 - GDW (1981)


Three major dating systems are in use when referring to historical events— Terran, Vilani, and Imperial.
Terran dates center on a year about midway through the period of Vilani ascendance. After that date, years ascend, and are suffixed AD; before that date, years descend, and are suffixed BC. There is no year zero.
Vilani dates (using a 496 day year) count from the year of the Establishment of the First (or Vilani) Imperium. Those before are suffixed PI (pre-lmperium); those after are suffixed VI (Vilani Imperium).
Imperial dates count from the year of the founding of the Third Imperium, specifying the year zero as a holiday year. Dates before that are negative, dates after that are positive, with the sign usually suppressed. Imperial dating also uses a Julian system for counting days. Each day in the year is consecutively numbered beginning with 001. Thus, in the year 1105, the first day of the year is 001-1105.
Zhodani dating is in olympiads (obviously a translation). Each olympiad is of three Zhodani years; each Zhodani year is 273 days. The first olympiad corresponds to 2209 BC. The dating system itself has been in more or less continuous use since then, with minor lapses due to war or temporary decline of ruling parties.
Adventure 3: Twilight's Peak, Pg.42 - GDW (1980)


Three major dating systems are in use when referring to historical events— Terran, Vilani, and Imperial.
Terran dates center on a year about midway through the period of Vilani ascendance. After that date, years ascend, and are suffixed AD; before that date, years descend, and are suffixed BC. There is no year zero.
Vilani Dates count from the year of the Establishment of the First (or Vilani) Imperium. Those before are suffixed PI (pre-lmperium), those after are suffixed VI (Vilani Imperium).
Imperial dates count from the year of the founding of the Third Imperium, specifying the year zero as a holiday year. Dates before that are negative, dates after that are positive, with the sign usually suppressed.
Imperial dating also uses a Julian system for days. Each day in the year is consecutively numbered beginning with 001. Thus, in the year 1105, the first day of the year is 001-1105.
Zhodani dating is in olympiads (obviously a translation). Each olympiad is of three Zhodani years; each zhodani year is 273 days. The first olympiad corresponds to 2209 BC. The dating system itself has been in more or less continuous use since then, with minor lapses due to war or temporary decline of ruling parties.
Adventure 2: Research Station Gamma, Pg.41 - GDW (1980)

Imperial Calendar: Calendar established at the creation of the Third Imperium as a universal calendar reform Dates count from the founding of the Imperium, the year “zero ” Dates before zero are negative, dates after are positive. For example, Terra discovered jump drive in -2431. The Imperium was founded in zero. Emperor Strephon was assassinated in 1116.
The year is divided into 365 standard days, which are grouped into 52 weeks of seven days each The lengths of days and weeks is a legacy of Terran domination during the second Imperium. Days are numbered consecutively, beginning with one. The first day of the year is a holiday and is not part of any week. For example, the first day (Holiday) of the year 1116 is 001-1116. The emperor was assassinated on 132-1116. The last day of the year is 365-1116.
Imperial Encyclopedia, Pg.27 - GDW (1987)


Screenshot 2026-05-30 035609.png


Traveller 5.10 - Core Book 1: Characters and Combat, Pg.262 - FFE (2019)


... And so on and so forth.
 
Sit down.

Are you sitting?

This may come as a huge shock...

The core rules for 12 months a year and 12 monthly mortgage payment which go all the way back to CT and are repeated in every version are contradictory to the Third Imperium setting calendar of a 13 month year...
 
Let it be noted that nowhere in canonical material does it specify that the Imperial calendar has any subdivision of roughly a month's size. The seven-day week is implicitly built in (see: 1day, 2day, 3day, etc. in the calendar printed in T5.10), but no other divisions. One may find Calendars in Charted Space of interest; this article was built up from information presented in canonical sources.

One may assume, simply because of Traveller-the-game's history, that the 12-payments-per-year structure of the mortgage was simply an import from the "real world", perhaps before any conception of an in-game calendar had been formulated. The specific structure of "20% down, then 1/240th of the purchase price for 480 months [read as: payment periods]" was probably written in to allow players to avoid having to figure out payments, interest rates, et cetera - this was early Traveller, not Attempts at Accuracy in Accounting.
 
Sit down.

Are you sitting?

This may come as a huge shock...

The core rules for 12 months a year and 12 monthly mortgage payment which go all the way back to CT and are repeated in every version are contradictory to the Third Imperium setting calendar of a 13 month year...

Yes. Thank you.

Because Traveller when it was created in 1977 was a generic Sci-Fi RPG. There was no setting, there was no OTU or Imperium, and a month and year were a simple month and year, and the rules were a simple game mechanic.

The OTU is a Setting. The Third Imperium in that setting uses a 365 day year of 13 arbitrary months of 28 days each. But the bank financial schedule for starship mortgages is still based on the 12 month per year payment cycle of the generic rules.

And the generic mechanics (and the setting) mandate an annual 2-week maintenance overhaul, and observe that this is when crew typically take their leave time.

All of the above is both Traveller-RPG history and OTU Setting Canon. No "house-ruling" is involved.


So for those who want to derail the simple questions of the new Traveller-player OP's thread with this tangent, perhaps you can give him a better interpretation of the above canon material than the "house-rule" that the schedule is laid out over 12 months at a slightly higher than 13-monthly payment rate in order to take the month of the 2-week annual maintenance period downtime into account? Do you have an observation to make for the OP and his questions?

The OP was asking questions to the community for his gaming table, not about pedantry.
 
Clasically, Traveller runs on weeks. One week in jump, one week in system, which gives time to travel to and from the world, buy and sell cargo and find passengers, have a variable amount of shore leave and maybe fit in an adventure.

Pretty much everything else is gloss. There's no real point in trying to micromanage your clocks or calender when every place has not only a different time zone, but MANY different time zones. It might be mid-day where the starport is, but it's midnight on the other side of the planet.

By all means, play up the quirks of the local planet's timekeeping for flavour, but it's sufficient to just tick things over in campaign weeks.
 
Do the Vilani group days into weeks?

Yearly mortgage terms would likely differ slightly on Vland.
Nothing in canon suggests it, but if you look at the Calendars in Charted Space article I linked to above, and do some quick calculations, one jump is just about 5.25 drandir (plus or minus the usual 10%). If they do have a sub-anno grouping of days, it wouldn't be unreasonable for their "week" to be five drandir.

Note that a ship mortgage would tend to be an Imperial thing, so that you don't have to return to a particular port of call every payment period - just stop in to any port of call that has a branch of the bank that wrote the mortgage, or a correspondent bank, and make the payment. So, a ship mortgage written anywhere, including Vland, would be for 20% down, then 480 payments of 1/240th of the purchase price, paid off at the rate of 12 payment periods in each year of 365 days of 24 hours each.

For mortgages that don't involve interstellar travel (e.g., non-jump-capable spacecraft, fixed-location facilities), local procedures and periods would govern.

Of course, if you want to mix your Traveller with Attempts at Accuracy in Accounting, you can always work out your own mortgages on the basis of the formula M=(Pr(1+r)^n)/(((1+r)^n)+1), where M is the monthly payment, P is the principle to be paid off, r is the monthly interest rate, and n is the total number of payments.

Edited: Don't take "monthly" for r above literally - it's actually the annual interest rate divided by the number of payment periods in the year.
 
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For mortgages that don't involve interstellar travel (e.g., non-jump-capable spacecraft, fixed-location facilities), local procedures and periods would govern.

But what about non jump capable spacecraft that travel on jump capable ships?
 
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