I'm needing to develop a calendar for my home world. I would like a year to be close to what we have in real life so that it doesn't play to much havoc with aging of characters. I'm looking at 10 or 12 months for the calendar and would be wanting 24 hour days.
One of the requirements I would need it to have is once a year, on the 6th month, both moons of the world are full in order to affect the lycanthropes of a particular swamp with an increased aggression. I would like this to fall only once per year, which is why I specify the 6th month.
I would like the math to be sound for my calendar. Is there someone that is knowledgeable about lunar and solar eclipses and determining when they would occur? Can a calendar be realistically designed in a way that the same days each month would work for eclipses each year?
Are there other considerations that should be taken into account when developing a calendar, other than naming the months?
If I use a 12 month calendar, with 28 days each all of the eclipses and full moons would be on the same day each year right?
If I add a 7 day period between the end of the 6th month and the beginning of the 7th month it would throw off the eclipses and full moons being on the same days each year right?
|
If I use a 12 month calendar, with 28 days each all of the eclipses and full moons would be on the same day each year right?
Certainly, assuming the moons have an orbital period of 28 days exactly.
If I add a 7 day period between the end of the 6th month and the beginning of the 7th month it would throw off the eclipses and full moons being on the same days each year right?
That would throw things off, yes.
Here's an idea:
Your world has 12 months of 28 days, for 336 days total. Let's say a "month" is defined by the larger moon, with an orbit period of 28 days. Astrophysics says the period of an orbiting object is determined solely by its distance from the parent body(the planet), so your moons cant have the same period of 28 days, they'd crash into each other(unless some funny cosmic magic is going on). So I propose that the smaller moon could have a period of some other fraction of 336 days. If it's farther out, it will have a longer period, if its nearer, a shorter one.
I found that if this fraction is an even number, or a factor of 12, your moons will sync up multiple times a year. So it will have to be an odd number, not a factor of 12(namely 3). What I mean is, if the larger moon is full 12 times a year, the smaller will have to be full an odd number of times.
Example:Larger moon is on a 28 day cycle, 12 full moons a year. Smaller moon is farther out, and has a longer period of 48 days, with 7 full moons a year. It syncs up on the 6th month, because you said so. 12 and 7 are nice mystical numbers, and you can call it the Lunar Conjunction, sounds suitably arcane.
I hope this helps, and that I made sense.
|
|
Ok, I just laid it out on a spreadsheet, and here are the dates for your full moons:
Big Moon is full on the first of each month.
Little Moon is full on:
Month 2, day 17
Month 4, day 9
Month 6, day 1 (Conjucntion)
Month 7, day 21
Month 9, day 13
Month 11, day 5
Month 12, day 25
You can move these dates around by adding/subtracting the same number of days to each. This is still just an example, if you want the other moon to have a different number of fulls per year than seven, just divide 336 by that number to get the period. Syncing it on the 6th month rather than the first is the trickiest part, you need to do some tedious counting or use a spreadsheet
Ok, here's the full write up I have thus far...
Darknoth is a world in which its single sun and two moons rotate around the planet in a twenty-four hour cycle to comprise one calendar day. There are thirteen months in one year of which each consists of 28 days, giving Darknoth a total of 364 solar days to a year. Each month consists of four seven day weeks.
This calendar system grants Darknoth the benefit of having every full and new moon, and both lunar and solar eclipses to land on exactly the same day of each month, every year.
Months and Days of the Week
The original calendar of Darknoth was implemented by the dragons when they taught astronomy to the more primitive species upon the planet as was such during the Glory of the Dragons Age. This calendar served Darknoth well and consisted of a ten month year, each with 36 days for a total year lasting 360 days. The name of the months was named after the different dragon specie colors. Each month consisted of six weeks and was named after the most revered of the dragons. Each week had six days of which were also named after other highly respected dragons.
The draconic calendar lasted until the Raising of Humanity. It was at this time that humans in their arrogance rewrote the calendar, developing the current system which honors their way off life rather than the dragons that raised them from their primitive nature. The current calendar is referred to as the Humantis System.
The Humantis System calendar grants each month a name based on its time of the year. These months are as follows;
Months................. Season
Deep Freeze............ Winter
Thaw Time.............. Winter End
The Awakening.......... Early Spring
Life Giver............. Spring
Green Leaf............. Spring End
Two Moons.............. Early Summer
Full Bloom............. Summer
Burning Sky............ Summer End
Harvesting............. Early Autumn
Falling Leaves......... Autumn
Airs Crisp............. Autumn End
First Snow............. Early Winter
Darkened Days.......... Winter
Weeks.................. Week Days
Lords Week............. Weeks Begin
Artisan’s Week......... Learnt Day
Laborer’s Week......... Labor Day
Slaves Week............ Mid Week
................................Money Changers Day
................................Family Day
................................Weeks End
Solar Bodies Across Darknoth Skies
The sun is referred to as Eclipses as a result of its shape. Not a completely round sphere any longer, the sun is slowly dying out. Rather than eventually bursting into a super-nova it has slowly been depleting itself of its precious gasses and darkening. The damage first began in a tiny spot on one side of it and it has slowly grown over the millions of years it has provided light to this part of the cosmos. The irreparable damage has caused it to take on a slightly crescent shaped, this giving it the name Eclipses.
The two moons that are held aloft in the heavens are called Night’s Eye and Black Pearl. Night’s Eye is the larger of the two moons and it rises much higher than its counterpart. The two moons begin on opposite ends of the sky and verge towards one another, crossing paths towards the end of the first quarter of the night and by early morning they are once again on opposite ends of the sky.
Black Pearl is a unique planetary body that absorbs light from both of the Eclipses and Night’s Eye rather than reflecting from them. The Black Pearl appears as a silhouette of black resting against the night sky. Once a year, for a seven day period, Black Pearl emits all of the light it has absorbed and this time frame always takes place on the first week of the sixth month. The first and last of these seven days gives off the least amount of light while the mid week gives off the most.
So what would I have to change to make this work? Would my moons collide or can they pass one another without incident?
Before I started playing in Golarion, I ended up making a very similar dedign choice: basic astronomy for the world and its moon are the same as Earth. That lets me use a real-world almanac. It saves a whole lot of time that can be used for more interesting design work. Because, honestly, how often does the calendar come up in play?
It's expected fluff when writing a manual for the world.
It's expected fluff when writing a manual for the world.
Who expects this particular bit of fluff?
Are you writing for publication and your agent/editor said you needed to include this? Or is it a standard you've set for yourself?Who will read/consult the manual?
Is this so you keep your own continuity straight, or are other people going to be relying on this manual to create their own adventures set in your world?
Is this a formal document that will be published somewhere so they can read it or is it something informal? Can everyone edit it or are you the sole writer who accepts suggestions and approves any changes?
I'm planning on making it available through Dungeon Masters Guild when I have enough material available. It will be served as small drop in pieces that other DM's can use in their own worlds and eventually as a larger whole piece package as my own world.
I set the standards on what information I feel should be available. This includes history of the world, kingdom descriptions, random encounter tables, NPCs, maps, and other descriptive information I feel is something that should be available when the time comes.
I pretty much put all of my gaming information together as a book, whether its D&D, Legion of Super-Heroes or Top Secret/S.I. It's the way I write and I enjoy putting the documents together in book form rather than loose notes.