So - in my musings I wanted or hope to immerse my group more fluff/flavor wise and as such had come up with my own Calendar late last year but have remained unsatisfied with the naming conventions I used.

It also goes to say that a Terran year differs from other "system" year cycles - if/when splitting scientific hairs LOL...

Does the Imperium use our Months of JAN, FEB, Etc. or have they adopted new names for the Months?

Are there even days of the week in 40k?

I'm not stressing Holidays too much cause of local customs and concerns would heavily influence that facet of the Calendar.

Thoughts, Advice, Wishes?

Stay GAMING

Morbid

I vote no. It's unromantic, but I think that just a decimal system would be used galactically.

Locally, what ever works for the planet/system in question. Then a geek correlates when

necessary to Terra Time.

http://wh40k.lexicanum.com/wiki/Imperial_Dating_System

Official Time (Numbers.M41) is said to be used primarily by Astropaths and Administorum, so they have a universal way to mark events, such as Tithe Payments. These are based on 1000ths of the Terrestrial Year. Otherwise, planets use a local time system based on what ever planetary period and culture they have. The Navy probably uses a Terrestrial based system, while merchant ships probably just use homeport time.

Yeah, like so many things in 40k, it can get really complex, plodding, and archaic. On the one hand, I can imagine an empire wanting a uniform scheduling system, and thus would use the same times, but that ceases to work as well away from a single world; even other planets in our own solar system can have drastically different "days" and "years", lengthwise. Now, add in that there are countless worlds, some ridiculous light years apart, and that barely even know what Earth/Holy Terra is, and yeah, it falls in.

With no backing, I'm still a firm believer in the practice of the Astronomicon having a small undercurrent in it, that basically just broadcasts the time stamp on the Emperor's homeworld, and any Navigator or Astropath can sense it; in this way, they can measure the passage of time from long journeys, where they have stars they may have never seen, and where some trips can take months, and some accidentally centuries, or arrive "before they left". If they can use some psykers as glorified cell phones, and others as a lighthouse for the cosmos, it doesn't seem so much a stretch to me that they could have some be a glorified clock, forever bellowing out the bell tolls of the days, as the Imperium continues to spread, ever outward, and/or die a little more, each day. Certainly, in places like the Koronus Expanse, so far removed from Earth, its people, its history, and blah, local time frames must matter, but for the Imperium to function as a whole, even the whiny, fragmented, inefficient whole it often is, some version of uniformity, some overarching commonality must exist. They all use the same gun, from Terra to Cadia to to Kulth, even if some areas might have an easier time making other things, and I feel that they must have some universal, even if only formally used, version of galactic timekeeping, and date management. Your milage may vary, and my grasp on the fluff, as it is and changes, may be dodgy, but in a game I'd run, at least, the Astronomicon chimes out the date on Earth, if you possibly care to know what that is, all the way in the Rifts of Hecaton.

Interesting... on a comedy basis, how does one say " see you next Tuesday " LOL (with no days of the week)

Has any GMs herein invented any names they use for days and months - it'd be interesting to see what some of you have used in the past...

BLAMMO !

to answer the spirit of the question, make up or find a nice fantasy Calendar, then use it

for the PC's home system. You may or may not need to relate it to earth-time.

All great suggestions. I run it as, most planets and ships with access to astropaths are aware of the Imperial timing system. But every planet, and likely many ships will have their own completely separate dating schemes. Some flotillas may share them, certain organisations may have their own universal time, star systems. Then there's planets where they have 5 calendars on one continent. 40k is kinda dumb, and doesn't always do the smart thing, but they always do it with style.

Personally I would if I was talking for an NPC just use our dating schemes, and then OOC afterwards say "Well yeah he doesn't say actually Tuesday, but like space Tuesday, like Saint Tyranius' day." The same way I use accents that I know how to do, or obscenities and slang I'm familiar with. That's not the exact term the character is using, in the same way low Gothic isn't English, but it's a close equivalent to the PCs involved.

If you wanna get all fancy with it, write down a few names for days of the week/months/holidays, to use as throwaway terms. The same way if you think about it for 3 seconds it's easy to come up with 40k slang. Sell the differentness of the setting a bit more.

other junk here:
https://community.fantasyflightgames.com/index.php?/topic/121150-time-synchronisation/page-2