Hello there,

Does anyone more steeped in 40K lore than I know if there are official names for all the months in 40k? With so many diverse cultures and so many planets within the Imperium, I imagine there are local names for months and local ways of splitting each planet's year, but as there are standard years for dating within the Imperium as a whole (presumably based on the Terran year), one would imagine there are Imperium standard months within that year too.

The only reference I have come across to the name of a month is this, from the Horus Heresy boardgame web page:

On the thirteenth day of Secundus, the bombardment began…

Presuming that is not just a local Earth month, but is used throughout the Imperium, if the rest of the months follow that simple pattern of using Latin ordinal numbers you would get this:

Primus
Secundus
Tertius
Quartus
Quintus
Sextus
Septimus
Octavus
Nonus
Decimus
Undecimus
Duodecimus.

Is that ever explicitly stated to be the case anywhere? It doesn't necessarily follow that all the months are named this way after all, as in our own calendar four of the months are simple number-based names (which don't even correspond to the actual number of the month concerned) and the rest have names based on other Roman stuff like Gods, Emperors etc.

I suppose another alternative is to use the actual Roman names for months, as High Gothic is usually represented as Latin or faux-Latin in the game.

Anyway, I shall probably use these for Imperium-wide, "Galactic" months, but if anyone has another list that has the backing of canon, I'd be very grateful if you shared it with us.

Thanks.

There are no formal months across the whole of the Imperium, so far as I'm aware.

Time references for the Imperium show a Terran year (365.25 days of 24 hours each) divided into 1000 parts for the purposes of timekeeping off Terra. So roughly 2.7 units per day. If you wanted to say 1st February, you'd say 0087, and so on.

This sounds mind bogglingly confusing, but actually makes sense - Earth's months wouldn't makes much sense on different worlds where they have their own, different months. The whole concept of a "month" is likely to be confusing to spacefarers (who don't experience seasonal changes) or inhabitants of worlds with very different seasons.

It may well be the case that on individual worlds, different months are adopted to give locals an ability to measure the change in seasons - this would even apply to Terra, which may have lost track of the names of the ancient months of the year. "Secundus" could be read as February.

Of course, I could be totally, wrong, but that's my take on it!

I've always described the Imperium as adhering dogmatically to the Gregorian calendar in my games, including in some severe cases following a 24-hour day even on worlds where it's substantially different. As far as a galactic standard is concerned however, the Adeptus Terra doesn't bother with weeks and months. They separate a year into 1000 fractions from 001-000. I would assume that most worlds are left to their own devices with naming structures for their calendars.

There are a number of fleeting background references which go for simple High Gothic numbers (try Crossfire, by Matt Farrer. I can't remember others of the top of my head), as well as a number of sources that go with "3rd month", "2nd week, 7th month" format (Gaunt's Ghosts, possibly others in the Abnettverse and I seem to remember it in the Inquisition War. May even be some in the Ciaphas Cain series).

I'd note that the official Imperial dating system doesn't lend itself well to a 12 month system (being wholly decimal), but given that the old, old roman calender had ten months (look up "Calendar of Romulus), and the Imperium has no need to honour deities other than the Emperor, then something like High Gothic numbering works well (also fits with the Administratum, who are probably the most numerous users of the official Imperial calendar).

That being the case, I'd set it as 1000 Days to a Year (use Chronosegment or Year Fraction if you must. *sigh*), with each Day being 8 hours 46 minutes (roughly). If there are 10 Months to a Year, that gives a Month 100 Days (which works out neatly as roughly 30 terran observed days). (my own personal corner of 40k also uses 5 Weeks to the Month).

Combine that with the High Gothic flavour and the list becomes

• Primus
• Secundus
• Tertius
• Quartilis
• Quintilis
• Sextilis
• September
• November
• December

Yes, those last three look lazy, but everything from Quintilis onwards is lifted directly from the Calendar of Romulus. Feel free to muck around with endings and declensions.

Hope that helps.

I wasn't imagining the Imperium imposing Terran months on all individual worlds irrespective of the length of their years, just thinking there was a need for an Imperium-wide subdivision of the year for dating purposes (so people and organisations from different planets are on the same page when the are talking about "when" something happened). I didn't know about the decimal division of the year. Thanks for that info. Clears things up.

With that in mind, If I am going to have "galactic standard months" I think it would make sense for there to be ten of them, then. I just like the idea of Latin-sounding month names rather than a Star Trekky-style bunch of numbers. However unofficially, I think alongside the numbering system, I will have some voidsmen using Terran months in my version of the 40k universe, while individual planets will have their own separate systems and names if they have a long history and culture, or just use the decimal numbering system if they are recent colonies or outposts.

Alasseo, I think you missed one off your list. It only has nine. I think you need an October in there.

Again, thanks for the help.