Three Dollar Quill

Let's just dump some notes on stuff in a category.

I've got a few solo campaign ideas in different systems kicking around, and one place where I tend to go above and beyond the recommendations of the rules—

—is in designing calendars. Dates, calendars, and holidays have always fascinated me and drawn my focus. This is an artificial system to keep track of natural events, but it also reflects and influences our culture, and even the world around us. I remember hearing about how some aspects of the weather are essentially on a seven-day cycle because they're influenced by human activity.

So, although it "is easy to keep track of" and "legible to general audiences" to either avoid dates, or to provide a relex of "normal" (read "Gregorian or maybe Julian") calendars when it comes to physical worlds, I like to see something more involved, in part because it situates the cultures that devised the calendar in the reality of their world, but honestly it's probably mostly that I like messing with the numbers.

With that background established, let's take some notes on the setting for a solo campaign that is... really not getting off the ground, for mysterious reasons...

(One brief disclaimer: none of this is admissable as a source for your homework or any other work; do your own research.)

I wanted to set the campaign on an Earthlike planet, but instead of giving it one moon-size moon, it has three smaller moons in Laplace resonance. The moons are all collinear once every sidereal month of the middle moon, so we ensure that it has an orbital period somewhat close to a month, to try to have something like spring tides. (This doesn't work astoundingly well because spring tides just rely on the synodic month when there's one moon, but having moons in resonance like this means that the sidereal months matter; possibly to deal with this, I will at some point endeavor to construct a synodic/sidereal lunar calendar specifically for tracking tidal effects.)

Because there are so many moons, and therefore also so many things that a moon could relate to, there are many possible options for calendars, moreso than the many options for calendars on Earth. The two initial ideas I came up with were a synodic calendar based around the inner moon with eight-day weeks, and a solar calendar that relates in some way to the synodic cycle of the middle moon, with six-day weeks. I haven't touched the latter in a while, and I've forgotten some of the details, so let's look at the former.

The days on this planet are slightly longer than on Earth, but near enough that using a twenty-four hour day results in an hour basically comparable to our own. This is what I call a concession to legibility. (And human-like physiology.) The long day just slightly overcorrects for a longer year, meaning that the tropical year of the planet is just over 361 and a third solar days. The synodic months of the moons are not-quite-sixteen days, not-quite-thirty-three days, and not-quite-seventy-and-one-half days.

So, each synodic month of the inner moon is just over two eight-day weeks. The accumulated error is very close to one day after eight months. To account for "sixteen days" sounding different from "a month", I call these sixteen-day periods "hextnights". Because "sextnights" sounds like a drastically different thing. I decide to have units of 8 hextnights called a "lunar season", in which one hextnight (probably the last one) is shortened by a day to account for drift.

Three lunar seasons is one or two hextnights longer than a tropical year, but I'd rather work with constant-length seasons, so I just accept that the lunar year is longer than it "could be". The lunar year is a decent approximation to the lunar cycle, requiring a further-shortened hextnight only around once every three hundred years. (This allows me to create a completely unintuitive meaning for the idiom "once a fortnight", and I'm very tempted to take that opportunity.)

I like this lunar year as a basis for a liturgical calendar, but I also want to adapt it do a solar civil setup. For this, I figured each solar year would be assigned 22 or 23 hextnights, depending on when the spring equinox falls relative to the full moon, and assigned a pair of numbers: 1 to 23 for the position in the year, and 1 to 8 for the position in the lunar season.

Putting this all together, we could end up with a date like: "CY 3307, Hx 13, 4/8, Waxing Week, Fifth Day (LY 4189, Fire Season)" (Or, if we go hardcore on the octal, "CY 6353, Hx 15, 4/10, Waxing Week, Fifth Day (LY 10135, Fire Season)") And I think that's neat.

Anyway, I spent way too long on this.

Good night.