A Simple Ogam-like Wheel

Charles has provided us with the Ogam Wheel based on a 13-month solar calendar. I've stated, that it could be modified to work with a 12-month calendar.

While neither disputing that it works well with a 13-month calendar nor disputing that a 13-month calendar was used, this I do not regard as essential to this kind of wheel.

I've come up with triple moon wheel that works with the Gregorian Calendar.

The outer wheel has the years of the Metonic cycle and a Star. The years 1995 to 2013 are positioned clockwise relative to the star as follows:

00: STAR
01:
02: 2008 Au#14
03: 1997 Au#03
04:
05: 2005 Au#11
06:
07: 2013 Au#19
08: 2002 Au#08
09:
10: 2010 Au#16
11: 1999 Au#05
12:
13: 2007 Au#13
14: 1996 Au#02
15:
16: 2004 Au#10
17: 
18: 2012 Au#18
19: 2001 Au#07
20:
21: 2009 Au#15
22: 1998 Au#04
23:
24: 2006 Au#12
25: 1995 Au#01
26:
27: 2003 Au#09
28: 2011 Au#17
29: 2000 Au#06

The Au# are the Golden numbers as used in the Easter rule ( (Year mod 19)+1). Years outside the range of 1995-2014 can be used by selecting the same year of the 19-year cycle (with same golden number).

The middle wheel has 30 phases of the moon as with the Ogam wheel.

The inner wheel has the days of the month running clockwise from 1 to 30 and then a 31 with the 1. It also has months at some of these numbers as follows:

10 Dec
11 Nov
12 Oct
13 Sep
14
15 Aug
16 Jul
17 Jun
18 May
19 Apr Feb
20 Mar Jan

To use the wheel,

Turn the middle wheel so that the FULL moon is by the YEAR in the outer wheel
Turn the inner wheel so that the MONTH is by the STAR in the outer wheel.

Then the days of the month indicated in the inner wheel are by their own moon phases in the middle wheel.

For 1900 to 2199, it also gives the correct Pascal Full Moons (if I'm correct). For other centuries, Gregorian corrections can be applied to the years in the outer wheel. The April 19 blip rule ensures that no year can ever occupy the star position (Pascal Moon April 19).

Example: 11 August 1999

For 1999, full moon is at position 11 in outer wheel.
August 15 is at the star (position 0).
So August 11 is at position 26 on outer wheel, opposite 11, 
indicating dark/new moon.


Example: 16 April 2003

For 2003, full moon is at position 27 in outer wheel.
April 19 is at the star (position 0).
So April 16 is at position 27 on outer wheel
indicating full moon.


Example: 26 July 2002

For 2002, full moon is at position 8 in outer wheel.
July 16 is at the star (position 0).
So July 26 is at position 10 on outer wheel
indicating moon two days after full moon.

Karl Palmen

26 July 2002