Domains and an Irregular Calendar

Here's an odd question. As I've been planning for a new game I'm planning to use a calendar with 13 months of 28 days instead of a standard 12 month calendar. This brings up some questions when I'm considering the domain rules.

1. how much of an effect (long-term) is the extra month likely to have in terms of calculations for domain growth, income, etc. Originally I had assumed that it was sort of a moot point as most of this was done on a monthly calculation and thus didn't matter much.

2. Domain Morale is checked every 3 months (the thing that sent up the red flag for me) which obviously breaks down great with 12 months, but not 13. I can obviously just break down the year by season and tinker but it does create an oddity.

I suppose, my question is really asking the more mathematically-inclined if you percieve any major sticking points or oddities that I should expect to crop up based on ACKS Domain Economics and a 13-month calendar year?

most of the ACKs math assumes 30 day months.  When I was running a play-by-post game, I used 28-day months for 12 months and just chalked up any irregularities to a kind of worldbuilding I didn't want to do.

I think overall as long as you're close to 30 days, it should all work out decently well, and 28 is similar enough.  the bigger problem is references to "Seasons" in some of the texts, which is likely to be broken by having 13 months since it doesn't divide into smaller whole parts of months. 

13 months of a standard 28 days would be an extra week every quarter, then, I guess?

Seasons would last 3 months, 1 week. That'd be the same time you'd check Domain Morale. I don't think that's much of a change. Heck, it's more consistent to say "each Season" rather than "every 3 months" anyway, for ACKS.

Only thing off the top of my head is that the switch from, say, Mercenary Availability going from the Week->Month->Season->Year depending on size of realm.

The seasonal availability you'd add another week's worth on to, and the year's availability another month's worth.

I'm kinda blanking on anything else that extends over a month?


Thanks for the quick replies. For what it's worth, the rigid calendar is a condition Law put upon this world when it won it away from Chaos in an earlier Divine/Mortal war. Some nations specifically don't use this calendar and it is a source of tension.

But yeah, I think it's easy enough to get by with the odd calendar, just wanted to make sure I wasn't missing something obvious.

I wouldn't stress about it.

At various times the Auran Empire campaigns have used a normal calendar, a 13 month calendar of 28 days each, and a 12 month calendar with 28 days per month with a one week holiday every three months. It didn't really impact the game at all. Only the most meticulous of players even noticed.


Yeah, my game world uses 12 30-day months in its calendar, with 5 festival days that are not part of any month.  The elves use a 13-month lunar calendar and a dozenal counting system that tracks years in groups of 12 (decade), 144 (century), 1728 (millenium), and so on.  The dwarves mark time in a completely different way, since their civilization tracked changes in the earth rather than changes in the sky.

Much to my chagrin, none of my players care in the least.  I have considered making the calendars and their interactions a major plot point from time to time, but it seems self-indulgent to force the players to engage with something that only seems to interest me.  If I ever work out a method to make my players give a damn about my time keeping apparatus, I'll be certain to share it.

In short, I think tracking domain mechanics by season rather than month will serve you just fine, and nobody will even notice if you fudge things by a day or two from time to time.

SClaytonU - My experience is the same. Or worse. They'd just as well have the dates in our calendar, even though the days and weeks are named for gods and heroes that don't exist in the setting. 


One thing I did to make calenders a bit more important was to look to the Mesoamercians. Their days had special significances with their deities and their totem animals that watched them. So, I had divine users that worshipped a certain deity become stronger in that deity's month. And people who had a specific totem animal would be more lucky on the day that belonged to that animal. It was in Savage Worlds, so a lot of it was giving Bennies to the characters, but I'm converting everything over to ACKS so I don't think it should be too hard.

Sometimes to get your players to care, you gotta give them that ever so slight mechanical carrot dangled in front of them :)

That's really good advice. What mechanics did you use?

So it was for savage worlds, which I also house ruled a little. Basically, characters picked their tonalli, which was their totem animal. If they adventures on that day, they’d get an extra Benny, which is like a hero point. Each month has a God associated with it and on those months, a divine caster could beseech their God for some small bonuses. I don’t recall then off hand since I’m at work.

Yeah, players are often unconcerned about the calendars in use. And that's fine. I'm do it for me. I like tracking the days and randomly announcing some sessions... "hey, you guys, it's been a year since you started adventuring."

Those moments, fleeting as they might be, make it worth all the effort.