Gloranthan Year Wheel, and Earth Correspondence

[PhilHibbs]

Thanks to Ellie and @Nick Brooke for inspiration and assistance.

SVG versions on the unofficial RuneQuest Glorantha Wiki:

 

https://runequest-glorantha.fandom.com/wiki/File:Gloranthan_Year_Wheel.svg

https://runequest-glorantha.fandom.com/wiki/File:Calendar_correspondence.svg

Edited December 7, 2020 by PhilHibbs
Fixed the year properly. for both leap and non-leap years

[Bill the barbarian]

So, looking over the chart, it shows Yule (winter solstice to most) falling at day 214. To the hive,  Is it celebrated in a similar manner to our worlds breaking of the growing dark and the return of light as the days ebb longer?

 

Oh and is the date correct, is this the lozenges solstice?

Edited December 4, 2020 by Bill the barbarian

[Stephen L]

5 hours ago, Bill the barbarian said:

Oh and is the date correct, is this the lozenges solstice?

Well, reading off the wheel Summer solstice is pointing towards Fireday, Harmony Week, Fire Season, which is Yelm's high holy day.  So that tallies, and looking at the Calendar supplied with the Game Masters Screen pack, all the solstices and equinoxes are marked there, and the dates tally.

So yes all the solstice and equinox dates are correct.

[Stephen L]

13 hours ago, Bill the barbarian said:

Oh and is the date correct, is this the lozenges solstice?

Although the real world dates for solstices and equinoxes are slightly out.  The lines shouldn't be at right angles to each other.  As an (former) astrophysicist I should know why.  Since I don't, I'll guess and see if anyone notices, but the Earths orbit is elliptical, rather than circular.  So the problem is the graduation for the real world days are all equal, if they varied to take into account the orbit eccentricity, then you could draw the solstice / equinox axis as perpendicular straight lines as shown in the figure.

[PhilHibbs]

15 hours ago, Bill the barbarian said:

So, looking over the chart, it shows Yule (winter solstice to most) falling at day 214...  and is the date correct, is this the lozenges solstice?

Fireday, Illusion Week, Dark Season. Which is what The Guide says, yes.

[PhilHibbs]

For @jenh and other southerners:

 

Edited December 7, 2020 by PhilHibbs
Fixed the year properly. for both leap and non-leap years

[PhilHibbs]

5 hours ago, Stephen L said:

Although the real world dates for solstices and equinoxes are slightly out.  The lines shouldn't be at right angles to each other.  As an (former) astrophysicist I should know why.  Since I don't, I'll guess and see if anyone notices, but the Earths orbit is elliptical, rather than circular.  So the problem is the graduation for the real world days are all equal, if they varied to take into account the orbit eccentricity, then you could draw the solstice / equinox axis as perpendicular straight lines as shown in the figure.

Oof. That sounds tough. Not sure if my trig is up to generating that, even if I did have the details of where the axes of the ellipse are in relation to the axial tilt in any given year.

[Stephen L]

10 hours ago, PhilHibbs said:

That sounds tough. Not sure if my trig is up to generating that

Given it's a couple of days here and there, I don't think it's worth the effort.  I should keep quiet and hope no-one notices.

[PhilHibbs]

Here is the Northern Hemisphere Leap Year version. Just because it's fairly easy (and I was born on a leap year).

(See top post)

I lined up the Spring Equinox on 20th May, which is correct for 1968, but the Autumn Equinox comes out to be 20th September instead of 23rd. If I line up the solstices instead of the equinoxes, then both the Spring and Autumnal Equinoxes come in about 2 days too early and late respectively. So I think this is the consequence of the elliptical eccentricity that @Stephen Lmentions in another thread.

 

Edited December 7, 2020 by PhilHibbs

[PhilHibbs]

I have edited the top post for a fully accurate correspondence to the equinoxes and solstices, taking into account the eccentricity of the Earth's orbit. The two years, leap and non-leap, were chosen to represent the average Glorantha fan*. Southern hemisphere done and added to the 6th post in the thread.

This is all UTC. So if you were born in a very different time zone, you might want to figure out what time you were born and convert that to UTC. Or just shift it in your head by the proportion of a day that your zone differs by. Counterclockwise for east of UK, clockwise for west. I think. CMIIW.

I forgot to put the dotted lines in that help trace from the inner to the outer calendar. I'll put them back in tomorrow.

* i.e. me and my brother, 1968 and 1966.

Edited December 8, 2020 by PhilHibbs