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Re: Phantom Day Ratios

by Brillig :: Rate this Message:

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Dear Karl and Calendar People,

 

My favorite calendar involving the number 161 is the one I mentioned a few years ago that has alternating months of 1 and 2 days. This pattern of alternating months repeats for 161 days, then starts over. Each year has 244 months.

 

Karl then modified this calendar, making months generally twice as long, having usually 3 days each, and occasionally 2.

 

These are discussed in the document http://the-light.com/cal/ve244.txt

 

Additionally, I came up with a lunisolar scheme of some sort. I’ve lost my notes, so I’ll have to reconstruct it, unless someone has a copy of the conversation where I mentioned it originally.

 

If you arrange the 1 and 2 day months described, above, into groups of 20, you have what I’ll call now a standard lunation. A lunation consists of 20 of these very short months.

 

The average length of a lunation with no adjustment, is 241/161*20 = 29.938 days. However, in http://the-light.com/cal/ve161m.txt I show how the pattern can be shifted either every 3 or every 4 lunations to get a better value for the mean lunation length. I don’t recall what the pattern of shifts was. With some rough calculations, it looks like a shift should occur approximately every 11/3 lunations.

 

I’ll see if I can find the original emails where I discussed this.

 

I also crocheted a Metonic cycle using this scheme. See http://the-light.com/cal/vecrochet0.jpg for an illustration. The crochet pattern consists of these 1 and 2 day months. A 1 day month is simply a double crochet. A 2 day month is two double crochets placed in the same spot, with the top loop being drawn through both stitches. The color changes every 161 days. Each row is a new year, so the Metonic cycle is given by 19 rows.

 

Victor

 


From: East Carolina University Calendar discussion List [mailto:CALNDR-L@...] On Behalf Of Palmen, KEV (Karl)
Sent: Thursday, January 08, 2009 9:57 AM
To: CALNDR-L@...
Subject: Re: Phantom Day Ratios

 

Dear Amos and Calendar People

 

Thank you Amos for giving this alternative, which I considered for a later note.

 

In general the calendar will repeat in as many years as  the numerator of the ratio (e.g. 293 years for the 364 date example).

However, if the number of dates per year has a common divisor with this numerator, the numerator divided by this common divisor would give the number of years. This happens in Amos’s example of 483 for 366 dates, which repeats once every 161 years and was first mentioned by Victor.

 

Amos has not considered any fractional approximations. Here are some:

 

366 482.977 483.105 483(365.242236)
367 208.784 208.807 209(365.244019) 208.8(365.242337)
368 133.440 133.449 133(365.233083) 400/3(365.24)  1201/9(365.242298)
369  98.196  98.201  98(365.234694)  98.2(365.2423625)
370  77.767  77.770  78(365.256410) 700/9(365.242857) 311/4(365.241158) 1011/13(365.242334)

 

Karl

 

10(04(12

 

From: East Carolina University Calendar discussion List [mailto:CALNDR-L@...] On Behalf Of Amos Shapir
Sent: 08 January 2009 15:31
To: CALNDR-L@...
Subject: Re: Phantom Day Ratios

 

How about the opposite type of solar calendars, those which have more dates in a year than days?  (I can think of useful calendars of at least 366 and 368 dates schemes).  Then, instead of "phantom days" which are date-less days, we'd have "phantom dates", which are day-less dates; that is, a date is skipped every N days.
 
Using the same method, I get the results:
 
366 482.977 483.105 483(365.242236)
367 208.784 208.807 209(365.244019)
368 133.440 133.449 133(365.233083)
369  98.196  98.201  98(365.234694)
370  77.767  77.770  78(365.256410)

Amos Shapir
 





Date: Thu, 8 Jan 2009 13:10:53 +0000
From: karl.palmen@...
Subject: Phantom Day Ratios
To: CALNDR-L@...

Dear Calendar People

There have been on this list a few examples of a solar calendar where a year has a fixed number of ordinary days between which are occasionally  inserted a phantom day.

Here I have a table that shows the ratio of ordinary days to phantom days for various numbers of ordinary days per year (column 1) for a mean year of 365.2422 days (column 2) and a mean year of 365.2424 days (column 3). You can get the ratio of days to phantom days by adding one to the ratio of ordinary days to phantom days.

Subsequent columns have a suggested approximation of the ratio followed by the resulting mean year in days enclosed in().

 

365  1507.019  1505.776    1507 (365.242203)    1506 (365.242364)

364   293.028   292.981     293 (365.242321)

363   161.895   161.880     162 (365.240740)  1457/9 (365.242278)

362   111.653   111.646   335/3 (365.241791)

361    85.097    85.093   85.1  (365.242068)  936/11 (365.242521)

360    68.673    68.671   206/3 (365.242718)

 

Karl

 

10(04(12

 

 

 

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