"Long time lurker, first-time writer, blah-blah..." ©Techpriest Horribus

Well, this topic just popped out during our roguetrader session.

Do anyone have any idea how do people on different planets synchronise time?

I guess it should be pretty important for administratum, but since in immaterium time goes different and even astropathic communications aren't important, it is a major problem.

I am aware of the check number in imperial dating system, of course: http://wh40k.lexicanum.com/wiki/Imperial_Dating_System#.VAgGd_l_v6A

But it looks like somewhere as far from Terra as Calixis, all dates will be class 4 or 5 at best since astropathic contact cannot verify time passed while message was en route.

I imagine there could be some kind of planetarium at major planets wealthy enough and whole cults of techpriest tempora astronomica devoted to time determination by watching the movement of suns. Watching Sol system to determine date makes this a class 2 source, as you are actually physically observe the system (by definition: " A 2 means that the event occurred while someone present for the event was in direct psychic contact with Terra or the Sol system". )

Less important planets could be synchronised by means of astropathic communication. Less accurate, this could determine current date anywhere within one standard imperial sector with an approximation of five weeks, accordingly to Navis Primer and makes these dates class 3 or 4.

Any more ideas?

P.S. oh. just realized that class 2 means direct PSYCHIC contact, not physic. That makes everything much more complicated and dates are so unreliable.

Welcome, blah-blah-blah

It's unlikely that they got one system of synchronisation. My bet is that most of worlds don't got any such system because: they don't need it.

The more I think about it ... is there a reason for Imperium to have such a system at all? I mean, for sure they would like to have it but do they really need it? - instead of something AdMech or Astropaths can achieve while not busy tring to synchronise time in 2/3 Galaxy, probly with use of hostile dimension of pure randomness, while fighting on all sides, and being eaten?

I mean people in Middle Ages hadn't been worried by diffrent times in diffrent towns, they've got better thing to worry about.

Maybe you're right, medieval, survival and all this stuff.

But also maybe you're wrong.

After all, there are planets and they must give its tithe. And administratum must count this tithe somehow. Like, "one hundred years since last tithe from Yaga Minoris, they have to bring, like, 240 megatonnes of cinnamon to date, and that is counted without interest"

And there are merchants, trade houses, rogue traders doing interstellar buisness. And business mean that time means a lot. Maybe not to the hour, I can agree that there is not any kind of developed bank system, but at least to the day or the month.

And maybe many more spheres of imperial life I cannot imagine right now but surely they need some way of knowing what time is it on Terra.

Yes, actually, there is need for a mostly standardized chronological system. It's appalling hard to coordinate the pickup and drop off of pretty much anything important if you're not using a mostly universal standard. For example, arrangements are made to pick up item X on planet Y and deliver to planet Z in year 892-893. But, because they're not on standardized timekeeping, the ship thinks it's 892 when it makes it to planet Y, but planet Y thinks it's 889, and when the ship makes it to planet Z, planet Z thinks it's 903.

Now, suppose that item X consists of vital military resources. Guard regiments, titan legion, etc. You begin to see the importance of standardized time.

At any rate, I'd say that anywhere that technology was maintained from the DAoT-era was and is synched with Terra; same for culture and knowledge of Terra, even if they had issues maintaining technology. Probably Forgeworlds are synched to an acceptable margin of error. I would venture an estimate that Forgeworlds also serve as hubs to locally synch. Remember, you don't actually need to use the Warp to know what time it is. You can utilize stellar maps and shifts, and do a bunch of math, or you can use lightspeed signals and some math. Now, the range you can use lightspeed signals from a given source is limited, which is why they'd have to use relays. Plus, there's the old idea that the AdMech secretly has some sort of limited non-warp communications system.

Also, I wouldn't really be surprised if the Astronomican had some sort of pattern to it that could be used as a temporal benchmark.

Administatum clerk have it's on callendar hanging on his office wall and doesn't need to know hour, month or year on cinnamon producing world. If they're late with this cinnamon (by clerk's callendar) he fill some paper work (in 3 copies) and moves on.

You can have your own time of Terra: some guy 1000 years ago magically manages to get Precise Time of Terra at given moment - now it's thats moments time + 1000 years. How you gonna check it's correctness? And qui custode custodes?

What's more important: knowing precisie time is irrelevant when you cannot predict travel time.

edit: ninj'd by javcs

Imagine XVI century shipments from New World to Europe - you've got some cargo, swim to Europe and when you there you sell it. Just that simple - and as a bonus - you've got a Astropath who, in normal conditions, can send a e-mail.

Also mind why Imperium use Crusades as they way to conquer stuff. Crusade doesn;t need to be in 24/7 contact with anything, it's just so big by istself to handle most situations.

Astrocomican can be obstructed or flicker so not so 100% sure.

You are making my brain hurt Wincent. The OP wasn't asking for advice on why you think it's irrelevant to have a standardized time. He was asking for assistance on coming up with concepts of how people and organizations could synchronize time with Terra.

Anyhoot, as javcs mentioned, a relay system would be best. Maybe several powerful Astropaths in a choir, linked with another Astropath choir on Terra via real time communication, and synchronized the time down to the minute/second. Once the time is down once, the math geniuses could figure out how to keep it accurate up to a certain margin of error, with scheduled periodic checks with Terra to ensure it's accurate. And so from that new location, that Astropath choir broadcasts real time to another location, to synchronize, and so forth and so forth. This way, when a ship exits Warp near a space station or planet that has this information, it can re-synchronize itself with the most accurate information, and the margin of error the Admech math genius postulated would be factored in via the 0-9 series mentioned in your link.

So with this approach (in theory), only the ships, space stations, frontier worlds, etc. that don't have this relay system in place would be way off with time synchronization due to Warp Travel and such.

And frankly, if I was one Battle Fleet coming from world A in Sector B, and had another Battle Fleet coming from world C in Sector D, and was planning a pincher move or flanking positions on an enemy fleet, that time difference would mean the life and death of my fleet.

"What do you mean our time synchronization was off by 20 years? I arrived at the correct time and date you requested to the T, according my clock. It's not my fault your fleet was destroyed and an entire Sector was enslaved to Chaos before I arrived with my fleet."

Sorry Nameless2all, hurting your brain wasn't my intend. My anwser to OP question was: they doesn't.

As to Battle Fleet I completly agree, but if they don't have a way to predict travel time what's the point of time synchronization? So it skip to question: does Battle Fleet you corebook, Navis Primer or house rules for warp tavel?

Now, if you excuse me, I'm gone for a long weekend. Cheers.

Well thanks for your input, some good ideas you have here!

I can't comment on Navis Primer rules because I do not own the book. Warp travel from known and stable routes in Sectors highly developed like Terra's shouldn't be years off or months off. Maybe days or possibly weeks if a Warp Storm hit the ship piloted by a Navigator. There are no rules for this so I'm just going off fluff. But you are correct that the fleets would not arrive at the same time due to warp variations during their travel. IMO though it would be better to be days or weeks off, than years or decades.

Happy travels though. My apologies if I came off hostile. Wasn't my intent.

In my head canon the Adeptus Administratum has a sub-branch called the Adeptus Temporis. They don't actually have the power to correct times and dates, but are in charge of pouring through the mass of new sensor logs and charts to identify "timepieces". These are astronomical phenomenon that can be observed to track time by common voidship augurs.

So it could be the decay of a particularly bright star, the pulsing of a nebulae, etc. Two or three of these celestial phenomenon can be used to approximate time. Astropathic contact is unreliable and the dates generated here would be Class 6.

The Adeptus Temporis maintains and updates these timepieces and distributes them openly to other branches of the Adeptus Terra. It's the "common clock".

As a Class 6 source, it also allows for nodal updates. So the Adeptus Temporis in one Sector that manage to get a Class 4 Corroborated Source will update its information and records and disseminate that to nearby regions as a Class 5 Sub-Corroborated Source.

So it's not just astronomical phenomenon but also psychic contact. It's the most "reasonable" way given the spread of the bureaucracy throughout the Imperium and allows for the necessary, though imprecise, dating that most people who care about the actual date (the Adeptus Terra) would rely on.

Indeed Astropathic messages aren't that uncommon, particularly not to a major world. It would not be particularly difficult for an administorum department to collect the timestamps and sent-from locations, then compare them to expected transmission times, perform the holy translation into leximechanical probability and compare the result to the great planetary clock. After 50 or 100 years, its not going to be too far off GMT.

Colonies or ships not in a civilized system have a more difficult problem, as they don't have the massive database of messages to 'average out' the unreliability of message transit times.

Your "pincer maneuver", the navy task force would almost certainly arrange to assemble the fleet at a very near by system, Set a synchronized mission clock. (T=0) then make the last couple lightyear jump at the same time, a distance for which the warp tides should affect them equally, or at least cause no more than a couple hour's difference (1-2 strategic turns)

The Imperium actually has a `date reliability` index for systems for just this wiggle factor. Terra is rated at 0, systems near Terra are at 1, and then as you get further away the numbers get higher. Since the Koronus Expanse is at the edge of the galaxy, it almost certainly would be a 9. The method according to canon is I believe roughly approximate to what it is here. If the Imperium was sensible, and it isn`t, they could just broadcast a continuous time signal from Terra and mathematically calculate the current time based off of the delay in the current signal they`re receiving.

Less canon is my belief that every Adeptus Mechanicus Magos to propose this has been laughed off of their Forge Worlds because everyone knows the machine spirits are too mischevious to allow such a coherent signal to be broadcast for thousands of light years.

To expand upon what Erathira said:

As for broadcasting a signal from Terra to use, well, if it's a light speed transmission, it'd only be 1000 light years out by now (1% of the way across the Milkly Way), if was a Psychic transmission, well, that has its own unreliability, and otherwise is covered by the above method.

That was the chart I was vaguely remembering, thank you.

The Imperium has existed for 10,000 years though, and Terra has been presumably beaming out signals for about 39,000 years so someone sensible - which I remind you are almost never the people in power - could have worked something out by now. At the very least the Segmentum Solar could have been put on reliable Terran Standard Time.

I'm really tempted to try to flesh out a group of Pilgrims who do nothing but ride through the Warp to try to hear a message from the Emperor over and over again, and that message is just the Emperor reading out the time and giving some information for Adepts to set their watches by.

To expand upon what Erathira said:

Class: 0/1 - Earth Standard Date. Referring to an event which happened within the Sol System. "0" is most commonly used to refer to an event which actually occured on Terra, while "1" refers to an event that occurred somewhere within the Sol System, such as Titan, the moon of the gas giant Saturn that serves as the headquarters of the Grey Knights Space Marines.

Class: 2 - Direct. The source for the event the date records was in direct psychic contact with the Sol System or Terra when the date reference was made.

Class: 3 - Indirect. The source for the event the date records was in direct contact with a Class 2 source, though not the Sol System itself.

Class: 4 - Corroborated. The source for the event the date records was in contact with a Class 3 source.

Class: 5 - Sub-Corroborated. The source for the event the date records is in direct psychic contact with a corroborated source.

Class: 6 - Non-Referenced, 1 year. The source for the event the date records is not in contact with a Class 0 to 5 source when the date reference was made, though it is a continuation of a timeline referenced by a Class 0 to 5 source.

Class: 7 - Non-Referenced, 10 years. As with Class 6 sources, but with a greater time span to allow for larger inaccuracies.

Class: 8 - Non-Referenced, 11+ years. As Class 7, though unsourced for a longer period of time.

Class: 9 - Approximation. For when worlds using a non-Imperial calendar must reference an event in that world's history.

As for broadcasting a signal from Terra to use, well, if it's a light speed transmission, it'd only be 1000 light years out by now (1% of the way across the Milkly Way), if was a Psychic transmission, well, that has its own unreliability, and otherwise is covered by the above method.

Yes, that's what I've been referencing in my first post, however the class description from lexicanum is a little different. Where've you taken this one?

Wouldn't they just use their telescopes to meaure the rate at which the universe is expanding? Seems like that would be a pretty solid way to get in the ballpark.

I've brought this up in other threads. Thanks for posting the times, Quicksilver. Keeping track of time is ultra-important, or at least I play it so in campaigns I've run. You cannot accurately navigate on Earth without accurate time, and I can't imagine that would become easier out in the stars. I make it so that navigators can't draw accurate charts of new routes without a recent time fix from the astropath. It makes the astropath more important, and gives the players an idea of some of the routines performed during flight in-system. I make the class of time corroboration a modifier on the navigator's astrography skill to make a star chart of the route. Sometimes it takes the astropaths days to establish time with any degree of accuracy. If you use RAW, then your astropaths won't even be able to do this till they're quite high rank, but the inability of astropaths to perform their main function (i.e. interstellar communications) is a topic for another thread.

I'm not going to lay out all the arguments pro and con for this concept. It's already been done before. Many people will simply want to hand-wave this away, but I find it adds atmosphere to my games.

Way i see it there would be Terran standard time, which would be a 24 or 25 hour day and a 12 month calendar year. This would be used as standard by most Imperial groups such as the Guard, Inquisition, Navy etc.

Local planets may use a different time system if their planet's orbit and rotation are particularly eccentric (no point referring to a 25 hour day if your planetoid takes 100 hours to finish a rotation). I'd imagine each planet with a time system deviating from Terran standard would have, as mentioned above, some kind of Temporis departmento that makes sure all incoming and outgoing paperwork and communications are decoded from Terran standard and recoded back to Terran standard once done.

I got that from the Warhammer Wiki, which tends to waver in it's reliability (Lexicanum is much more careful about sourcing, but this can lead to outdated information.), however the descriptions they use are clearer and make a little more sense to me then Lexicanum's.

The way I usually run in the fluff is that unless you're at a young colony (or weird stuff has happened) planetary time is considered highly reliable. It's been checked 40k times and they have things like pulsar counts, atomic clocks and the like to keep them from drifting too far between checks. (Remember that physics are not nearly as reliable in their universe as they are in ours). It's colonial and shipboard times that tend to be hazy.

According to what I've seen, the Imperial Dating System is done Metricly. So each year is divided into 1000 equal parts (8.5 Standard hours, btw) and counted sequentially from the new year. Of course, it's also said that the Administratum and Astropaths are the only ones who ever use this system. Everyone else just uses planetary time.

Ummm....the sticky point, which Rogue Traders frequently run into, is that time in the physical world and time in the warp don't pass at the same rate. Therefore, when a ship exits the warp, no clock, no matter how accurate, can tell them what time it is. Not having a clock, they can't draw a map showing the route they traveled to get where they are. They can probably get back to where they started, but they won't be able to tell others where they were or how they got there. It's an experiment that cannot be easily repeated.

Planets can use whatever time they want. Starships need a standardized time. They need to constantly reset their clocks, and they need a reliable method to determine fluctuations in time during warp transit.

The Astronomican.

It won't tell you what time it is, but if we go back to before clocks were invented, being able to accurately measure the passing of the sun allowed for navigation during the day and by stars during the night.

The Astronomican doesn't really set, but it could easily "pulse" regularly or have some other regular effect that allows a Navigator to say "After three beats of the Astronomican, turn left-inwards to the feeling of regret after eating cold pizza then sail on the purple yam highway for two beats" which is probably what those warp charts are.

No need to inflate the already crucial role astropaths play to make them telepathic timepieces.

Marwynn, if you go back to the time before clocks were invented, navigators were able to determine latitude in a number of ways, albeit not so accurately until declination was understood. They were not, however, able to reliably (not to mention unlaboriously) determine longitude until a portable and accurate clock was invented.

Early methods include "dead reckoning" or simply guessing how far one had traveled that day. If you've seen early explorers' maps of the Americas you might have noticed that they are pretty accurate from north to south and way off from east to west. The method of navigation back then was to get away from shore, sail north or south until you reached the latitude of your target destination, then sail east or west until you hit land and hope you recognized a landmark that ancient mariners' maps are so full of.

Other methods included sighting various heavenly bodies (usually only done at night) at distances from other heavenly bodies. The problem with this method in Rogue Trader, aside from the fact that it wasn't even very good in the 1600s and 1700s, is that sighting heavenly bodies isn't as easy as you might think, evidenced by all that missing matter in space called "dark matter." Many stars simply aren't visible from very far away, even with sophisticated instruments.

Of course, some people are going to make the argument that you only need 2 or 3 reliable stars, but having exited the warp it might be very unreliable to assume that the large blue mass in your megascope is Oxymoron VIIb. And, I wouldn't assume, either, that 2 or 3 stars would give one an accurate picture of 3D space. It's barely enough for a 2D ocean surface.

I think that in Rogue Trader, as on Earth, a timepiece would prove the most accurate, reliable, and well...timely.

Knight,

That really depends on how accurate you want your warp travel as well. By your theory and methodology, if you had a good astropath (time) and good maps, then fairly long jumps would be possible without a Navigator.

I, however, prefer to think it's more like pre-longitude navigation, where you have to stick to places where you can see something as reference.

Don't forget that the Astronomican isn't the only thing that can be seen in the warp, its just the most reliable and specific. (I figure it's used mostly to orient exactly which way the ship is pointed.) Warpstorms, like the Eye of Terror, would also be visible, as (arguably) are other things that have a great influence on Time-space, such as stars. They're just not necessary visible for very far. But if you watch them go by, you can count or use them to verify your going mostly along the right track. If you're not sure, or if your sight is getting obscured, you might drop into realspace to verify your exact position triangulating from big stars, or just checking the local star's spectra against your massive library of navigational data (you did bring one didn't you?). By the descriptions given, even ships with navigators drop out every so often to check their location - they can just go farther than those without navigators (who are limited to about 5 light years per jump).

But hey, it's all very washy, so you can always salt to taste.

That's just it, Quick. It's all about taste, and not yours, but that of your audience. Some people have a bread and potatoes audience. Some want meat. Some like spicy. I was throwing out a piece of meat for those who might want some.

I, too, go for the "it's all very fuzzy" atmosphere, but there's still a lot of technicality behind the fuzziness.