Constructing Calendars

Do you know how long man kind has been trying to keep track of time? Since like, forever. Since the Neolithic era when they build huge stone monuments to track the movement of the sun and stars. I went down the Google rabbit hole on this one and over the course of human history we have tried very hard to keep track of our days, months, and years. This is a really fascinating subject which I might get into at a later date. But not today.

Today I want to talk about what got me started on this line of questioning in the first place. And that was the fact that Phil and I wanted days of the week and names for the months in Galhadria. Dustin had been fairly resistant to this idea, but I was like “Come ooooon. Can’t we just slap some alternate names on days of the weeks and be done with it? We’ll just say a year is 12 months. It’ll be fiiiiine.”

But really, it was not fine. Buckle up kids, because it’s about to get really complicated.

An ancient orrery.

Galhadria is actually an earth sized moon orbiting a gas giant planet, Uhel, (pronounced like yule) which is of course orbiting a star. To really, truly, calculate the lengths of days, weeks, months, years, etc, it would probably take an astrophysics degree. So we’re doing what Dustin refers to as “handwavium” to make things work out and feel more Earth like and familiar. But I still really wanted to consider giving some months some days and maybe days of the week. So here we go:

*Please note, Great Uhel and Uhel are used interchangeably.

Generally speaking, a day is roughly the equivalent of 24 hours, and Galhadria has four seasons like earth. Yay handwavium! So far so good. But this is where even with handwavium, it starts to get complicated. People on Galhadria consider Uhel, which is the gas giant they orbit, to be a moon in their sky, and since it is the biggest, largest one, they measure by it.* This means one lunar month on Galhadria would be new moon Uhel to new moon Uhel. One full orbit of Great Uhel would take approximately two earth months. So, one lunar month would be roughly 60 days.

HOWEVER. To try to keep things as familiar as possible, which would be 12 months making a year, a year having around 360-ish days, Galhadrians measure a month from new moon Uhel to full moon Uhel. Simple, right?

*You can measure years in both lunar and/or solar cycles. Which can get really tricky, because on Earth, for example, the lunar years and the solar years don’t line up. We orbit the sun every 365.2563 days-ish. I say -ish because this number changes over time. Our lunar year is only 354 days. (A set number of times that the moon goes from new moon to new moon.) I told you, this gets SUPER complicated really quickly. What blows my mind is that people all the way back to ancient times noticed this and tried to account for it. Julius Cesar came up with the concept of ‘leap year’ to keep holidays occurring in the same seasons, but it wasn’t super accurate. In the 8th century a monk name St. Bede figured out that the calendar had drifted by at least 3 days and 500 years after that scientist Roger Bacon noticed it was a whole week off. So they made up the Gregorian Calendar, which is what we use now. You can learn more about all of this HERE.

ANYWAY! Back to Galhadria.

Great Uhel orbits it’s star in what is roughly the equivalent of 18 to 20ish Earth years.

Further, we’ve attributed the changing seasons more to axial tilt just like on Earth. (Contrary to popular belief, it is the tilt of Earth’s axis, NOT it’s distance from the sun which creates our seasons. In the northern hemisphere Earth is actually farther away from the sun in our summer time, but because of how we are tilted during the summer we get more sunlight than we do in the winter.)

So a year in Galhadria is measured from one winter to the next winter, a full changing of the seasons. Therefore their year is measured not by the solar calendar, but mostly by the lunar calendar, and a month would consist of a half change of Uhel (From new to full or from full to new) as one month. If it sounds complicated… that’s because it is. I can’t wait to explore the cultural implications of this in our world building. I’m kind of geeking out a little bit.

If you followed any of that at all, I am amazingly impressed and congratulations are in order. Nice job! Stay tuned because I’m working on an actual lunar calendar for Galhadria, complete with months of the year and days of the week AND Holidays and festivals!

Till next time dear reader, I encourage you to follow the link I provided and go check out the history of our calendars. <3 - Tiff