We had a character creation session and tomight I am formally starting my first Traveller Campaign.  I have designed a subsector and was thinking about the concept of time.  Obviously each world would have its own time system that is probably based in length of solar day, time to orbit sun, or some other factors.

I am not using third imperium and no alien sophonts have been revealed at the start of the campaign.

From a Julian calendar Earth point of view I have said we are starting at the equivelant of 2747.  Characters in this campaign will never reach earth, however, as it is too far away.

What do you do for a standardized "star date"?  Simple is good.  Thanks.

IMC, the calendar is the slight holdover from Cradle (Earth, Terra, Tellus- now a preserve and tourist site).

Dates are kept track by day, week, and year. Communications and cargo are kept track at the weekly level (17-2725). Sometimes the month is noted numerically, but that's considered archaic. 13 months, by the way. Names of days are remembered, but spotty. Month names are mostly lost except to historians.

Same as the new Star Trek movies.  Year.Days in that year.  Like 2747.1 would be January 1, 2747.  2747.35 would be February 4, 2747.  So, it would go from 2747.1 to 2741.365 (or 366 if it's a leap year, which it isn't).

My campaign is centered around a lost Terran colony, originally 1 world but those pesky humans have expanded to over half a dozen worlds.  The calendar starts with the founding of the colony as year 0.  Standard year length and day length (for game purposes only) is set to Terran "norm" 360 days, 24 hours no leap year.  When months and weeks are used, weeks are 6 days long, 5 weeks to each month, 60 weeks to the standard year.

Standard Gregorian calendar.  In-game, it's because of long-standing tradition dating back to when humanity was stuck on just one planet.  Out-of-game, it's because I don't see any particular value in requiring the cognitive overhead of everyone remembering how a fictional calendar works.

Quote from: Vic99;951917What do you do for a standardized "star date"?  Simple is good.  Thanks.

Depends on what planet a character is from, and what that planet used for telling time. None of that matters though if your players are not role-players.

Quote from: Celestial;951944Same as the new Star Trek movies.  Year.Days in that year.  Like 2747.1 would be January 1, 2747.  2747.35 would be February 4, 2747.  So, it would go from 2747.1 to 2741.365 (or 366 if it's a leap year, which it isn't).

Thanks for all the input.  I went with this.  Cheers!

Quote from: Vic99;951917We had a character creation session and tomight I am formally starting my first Traveller Campaign.  I have designed a subsector and was thinking about the concept of time.  Obviously each world would have its own time system that is probably based in length of solar day, time to orbit sun, or some other factors.

I am not using third imperium and no alien sophonts have been revealed at the start of the campaign.

From a Julian calendar Earth point of view I have said we are starting at the equivelant of 2747.  Characters in this campaign will never reach earth, however, as it is too far away.

What do you do for a standardized "star date"?  Simple is good.  Thanks.

I know that I am late to the party here, but a time measuring system I always wanted to try was one used by Joan D. Vinge in her Heaven Belt stories. Metric seconds. A kilosecond is 1000 seconds, a megasecond is 1000000 seconds and so on.

I use two calendars. One is the Standard Reference Calendar, the other is the various local calendars. Local calendars are based on planetary solar years, etc. Every computer includes an automatic conversion program that gives the Standard reference dates and times as well as local.

Remember that on Earth before the railways all time was local time. There was no need for "standard" time across time zones.  With interstellar travel being expensive most people only need to concern themselves with local time.

I like the idea of metric seconds, Jeff.

Dave, the local time point is a good one, but since my universe revolves, at least in part, on the PCs, I wanted to be able be consistent as the game progresses.

Time zones for each planet charted for the star sector your using, it's too much work trying to figure out planetary rotation and and orbital patterns of each body in your sector, if time is that relevant in your campaign,  chart each worlds time zone, when you arrive at destination check that planets chart info for time adjustment  , or if you have hours it takes the in question planet to rotate one full rotation such as day equals 36 hour rotation just pick a hour of arrival that fits the best impact for your story and run with it. Charting each planet is most accurate for a Traveller game, but you might discover a better way of doing it.

Never occurred to me to use anything but the regular calendar, but it never mattered as far as I can recall. "We need to deliver this crate in three weeks" was about as much as it mattered.

I remember having a metric clock as a kid back in the 70s. It was just from 1 to 10 and I think it has 100 minutes for every hour (and metric seconds).

But in my space games, I just use Earth dates unless they are on the planet for a long time (where I figure out the local time system)

Here is the current definition of a second as a unit of time. That definition could change based on the world that is using it, and what radioactive isotopes they have to make atomic clocks with. A society centred on a specific planet or system will likely use some time system derived from the main world. Or maybe if they wanted something that could work on a galactic scale, maybe they could measure some cosmic background radiation from the galactic core which is constant. That way, you can keep time relative to the heart of the galaxy even when space travel creates a time dilation. I mean, you probably have to stop the ship and point the antenna for a while to sync the clock, but it could work anywhere.

The idea of metric time is pretty neat. That could certainly be handy for a starfaring society which doesn't base their time on one specific world. Things like hours and days and weeks and months might have little meaning to someone who lives on a ship or on a station most of the time. For a society which is not tied to the rotation and/or orbital cycles of a planet, a metric approach would make a lot of sense. They might even decide a second is arbitrarily defined as 10 billion periods of transitional radiation of Cesium 133 making it 1.08782776 Earth Seconds. They might have something like 60 kiloseconds of activity and 30 kiloseconds of sleep per 90 kilosecond cycle (27.195694 Earth Hours or 25 local hours based on a 10 billion period Cesium 133 second). A six day "week" would be around 540 kiloseconds. So maybe for the sake of math and being metric we could clean it up. Make the Activity Cycle/Day 100 kiloseconds, with work cycles of 10-30 kiloseconds, 30 kiloseconds required for natural sleep, and the other 40 kiloseconds for doing whatever. That's around 27.77 Earth hours. A five day "week" would be 500 kiloseconds (5.79 Earth Days). You could bring it up to a "fortnight" of 10 Activity Periods which would be 1 Megasecond. An Earth Month would be about 2.59 Megaseconds and an Earth Year is about 31.54 Megaseconds. So really you can pick units you like that work out to nice even numbers. Maybe your "Month" of 30 Activity Periods is 3 Megaseconds and maybe your "year" is 30 Ms. Map out durations of important things and then maybe go from there.

Quote from: nDervish;952104Standard Gregorian calendar.  In-game, it's because of long-standing tradition dating back to when humanity was stuck on just one planet.  Out-of-game, it's because I don't see any particular value in requiring the cognitive overhead of everyone remembering how a fictional calendar works.

That's pretty much the direction I lean.