Dear Brij and Calendar People In his DividebySeven and DividebySeven leap week rules
Brij offsets the leap weeks that are in addition to the regular leap weeks
every seven or six years to reduce the jitter rather than have two leap weeks
in some years as Marcus Wong has proposed. I’ve thought about how much this would reduce the
jitter by and I came to the conclusion that it would reduce the jitter by exactly
the same amount as the drift of the calendar year against the mean year over
one cycle of the regular leap weeks without any additional leap week. I
leave it to other calendar people how I came to this conclusion about the
jitter reduction. Next I give it in more detail. For DividebySeven, and offset of two or three years would
reduce the jitter by the difference between seven mean years and a seven years with
one leap week. This works out as 7*365.2421875 – 7*365 = 1.6953125 days for a mean year
of 365.2421875 days and 7*365.2425 – 7*365 = 1.6975 days for a mean year of 365.2425
days. This applies regardless of the intervals between the
additional leap weeks, provided of course they are divisible by seven years. For DividebySix, and offset of one, two or three years
would reduce the jitter by the difference between six mean years and a six
years with one leap week. This works out as 6*365.2421875 – (6*364 + 7) = 0.453125 days for a mean
year of 365.2421875 days and 6*365.2425 – (6*364 + 7) = 0.455 days for a mean
year of 365.2425 days. This applies regardless of the intervals between the
additional leap weeks, provided of course they are divisible by six years. It
may also apply if the offset is varied so the intervals are no longer divisible
by six years. The fewer additional leap weeks there are to offset, the
less the reduction in jitter arising from this offset. Karl 11(08(28 

Dear Brij, Karl Palmen and Calendar People
Interesting readings, but far too complicating in my opinion. Willy Date: Wed, 6 Oct 2010 13:10:48 +0100 From: [hidden email] Subject: Jitter Reduction from Offsetting Additional Leap Weeks in Divideby7 & DivideBy6 Leap Week Rules To: [hidden email] Dear Brij and Calendar People
In his DividebySeven and DividebySeven leap week rules Brij offsets the leap weeks that are in addition to the regular leap weeks every seven or six years to reduce the jitter rather than have two leap weeks in some years as Marcus Wong has proposed.
I’ve thought about how much this would reduce the jitter by and I came to the conclusion that it would reduce the jitter by exactly the same amount as the drift of the calendar year against the mean year over one cycle of the regular leap weeks without any additional leap week. I leave it to other calendar people how I came to this conclusion about the jitter reduction. Next I give it in more detail.
For DividebySeven, and offset of two or three years would reduce the jitter by the difference between seven mean years and a seven years with one leap week. This works out as 7*365.2421875 – 7*365 = 1.6953125 days for a mean year of 365.2421875 days and 7*365.2425 – 7*365 = 1.6975 days for a mean year of 365.2425 days. This applies regardless of the intervals between the additional leap weeks, provided of course they are divisible by seven years.
For DividebySix, and offset of one, two or three years would reduce the jitter by the difference between six mean years and a six years with one leap week. This works out as 6*365.2421875 – (6*364 + 7) = 0.453125 days for a mean year of 365.2421875 days and 6*365.2425 – (6*364 + 7) = 0.455 days for a mean year of 365.2425 days. This applies regardless of the intervals between the additional leap weeks, provided of course they are divisible by six years. It may also apply if the offset is varied so the intervals are no longer divisible by six years.
The fewer additional leap weeks there are to offset, the less the reduction in jitter arising from this offset.
Karl
11(08(28
 Scanned by iCritical. 
In reply to this post by Karl Palmen  UKRI STFC
Dear Brij and Karl Palmen and Calendar People
For better or for worse, the Gregorian Calender after Pope Gregor XIII, is what we have chosen in the near and farther future. Here are som thoughts that are far too simple.
Once the idea of leaving every 128 Years with only 365 days was abandoned, every (sic) now and then, 128th years should change down to every and once 100th Year. Instead it was chosen to give ordinary 100years 365 days. And here comes the question, when each and every year divideable by 100, only get 365 days. What could be done next, some years to decide what to do, 1 and 2 days off course.
Years divideable with 80 now gets only 365 days. And in the beginning, or what should it be called, years that are divideable with 400 will get 366 days. Somewhere in a distant future every 80th Year only have 365 days, all and everybody are long gone.
Another question is, will this " Be a legal Calendar or a legal Calendar change ?"
A Calendar with "Leap weeks" seems too far a guesswork. One thought who could bring me down, or more severe punishment, is making Easter the Last Week in March, here I must abstain.
Name of the Calendar?
Of course good ol' Pope Gregor XIII
Kind Regards Willy 
There's a History HackDay happening in London 22nd23rd Jan 2011
http://historyhackday.org/ http://historyhackday.pbworks.com/ http://twitter.com/#!/historyhackday could be interesting. 
In reply to this post by Willy Juul Krogh
Dear Willy and Calendar people From: East Carolina University Calendar
discussion List [mailto:[hidden email]] On Behalf Of Willy
Juul Krogh Dear
Brij and Karl Palmen and Calendar People
For
better or for worse, the
Gregorian Calender after Pope Gregor XIII, is what we have
chosen in the near and farther future. The Gregorian calendar has a jitter of 2.1975 days, which can be
seen by comparing the actual number of leap days in the 193year interval 1903
to 2196 inclusive with the average number of leap days in 193 years. Here
are som thoughts that are far too simple.
Once
the idea of leaving every 128 Years with only 365 days was abandoned, every
(sic) now and then, 128th years should change down
to every and once 100th Year. The 128year cycle calendar has a jitter of 1.6953215 days got
by comparing the number of leap days in the sevenyear interval 125 to 131
inclusive (which is zero) with the mean number of leap days in seven years,
which is (31/128)*7 = 1.6953125. Instead
it was chosen to give
ordinary 100years 365 days. And here comes the question, when each and every
year divideable by 100, only get 365
days. What could be done next, some years to decide what to do, 1 and 2 days
off course.
Years
divideable with 80 now gets only 365 days. And in the beginning, or what should
it be called, years that are divideable
with 400 will get 366 days. Somewhere in a distant future every 80th Year only
have 365 days, all and everybody are long gone. This is beyond me. It may refer to the distant future when the tropical
year is less than 365.24 days.
Another
question is, will this " Be a legal Calendar or a legal Calendar change
?"
A
Calendar with "Leap weeks" seems too far a guesswork. See more about leap week calendars at http://www.hermetic.ch/cal_stud/palmen/lweek1.htm
The note you have been replying to is about a particular class
of leap week calendars that are in my opinion not the best. It says the a
particular feature of these calendars (the offsetting) gives just a small
benefit in reducing jitter. The reduction of jitter by about 1.7 or 0.45 days
is small compared with the jitter of such calendars which is about 14 days at
best. A similar issue applies to some sidereal leap day calendars. For
example, one could have a leap day every four year plus an additional leap day
every 160 years (mean year 365.25625 days). Such a calendar would have a jitter
of 1.74375 days (over the oneyear interval of year 160). If the extra leap day
that occurs once every 160 years were offset two years, then the jitter would
be reduced by the error over 4 years, which is 4*(1/160) = 0.025 days to 1.71875
days; not a big improvement. One
thought who could bring me down, or more severe punishment, is making Easter the Last
Week in March,
here I must abstain. Or the first week in April, or whatever.
Name
of the Calendar?
Of
course good ol' Pope Gregor XIII
Kind
Regards Willy Karl 11(08(29 

In reply to this post by Willy Juul Krogh
WILLY, Karl, sirs:
>Dear Brij and Karl Palmen and Calendar People >Once the idea of leaving every 128 Years with only 365 days was abandoned,..... When was this? Surely, this must have happened after the Papal Bull of 1582! Does this mean NO correction to 'calendar format be considered  for improving the Mean Year value; the very purpose of Pope Gregory's work that caused deleting 10days out of calendar. Please see the formats I have been discussing and placed at my Home Page: http://www.brijvij.com/ and my Leap Weeks plan using 896year/159 LWks on div.6; div.7 or even div.8 to give IMPROVED mean year =365.2421875 days instead of 365.2425 days. Please see: http://www.brijvij.com/bb_DIV_7plan.pdf I shall be temporarily out of doing any calculations since I shall be away attending to my my wife who has undergone surgery. I shall, however, read occasional reactions. Regards, Brij Bhushan Vij 20101008H00:21(decimal) EST Aa Nau Bhadra Kritvo Yantu Vishwatah Rg Veda The Astronomical Poem (revised number of days in any month) "30 days has July,September, April, June, November and December all the rest have 31 except February which has 29 except on years divisible evenly by 4; except when YEAR divisible by 128 and 3200  as long as you remember that "October (meaning 8) is the 10th month; and December (meaning 10) is the 12th BUT has 30 days & ONE OUTSIDE of calendarformat" Jan:31; Feb:29; Mar:31; Apr:30; May:31; Jun:30 Jul:30; Aug:31; Sep:30; Oct:31; Nov:30; Dec:30 (365th day of Year is World Day) ******As per Kali VGRhymeCalendaar***** "Koi bhi cheshtha vayarth nahin hoti, purshaarth karne mein hai" My Profile  http://www.brijvij.com/bbv_2colvipBrief.pdf Author had NO interaction with The World Calendar Association except via Media & Organisations to who I contributed for A Possible World Calendar, since 1971. HOME PAGE: http://www.brijvij.com/ Contact via Email: [hidden email] Date: Wed, 6 Oct 2010 15:36:57 +0200 From: [hidden email] Subject: Re: Jitter Reduction from Offsetting Additional Leap Weeks in Divideby7 & DivideBy6 Leap Week Rules To: [hidden email] Dear Brij and Karl Palmen and Calendar People For better or for worse, the Gregorian Calender after Pope Gregor XIII, is what we have chosen in the near and farther future. Here are som thoughts that are far too simple.
Once the idea of leaving every 128 Years with only 365 days was abandoned, every (sic) now and then, 128th years should change down to every and once 100th Year. Instead it was chosen to give ordinary 100years 365 days. And here comes the question, when each and every year divideable by 100, only get 365 days. What could be done next, some years to decide what to do, 1 and 2 days off course.
Years divideable with 80 now gets only 365 days. And in the beginning, or what should it be called, years that are divideable with 400 will get 366 days. Somewhere in a distant future every 80th Year only have 365 days, all and everybody are long gone.
Another question is, will this " Be a legal Calendar or a legal Calendar change ?"
A Calendar with "Leap weeks" seems too far a guesswork. One thought who could bring me down, or more severe punishment, is making Easter the Last Week in March, here I must abstain.
Name of the Calendar?
Of course good ol' Pope Gregor XIII
Kind Regards Willy 
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