Correspondence
Noah's Calendar Query - Patrick Greene
Calendar Page Appreciation - Amos Alter
Date of the 2nd Temple's Destruction? - Jack Lipinsky, Ph.D.
Prayer For Rain Insertion - Ari Meir Brodsky
Oddly Mysterious Coincidence - Dwight Blevins
Extension of Questions 143 and 145 - Larry Padwa
What Are the Months' Lengths? - Pete Ryder
Origin of the Hebrew Year Count? Researcher A
Proposed Hebrew Calendar Modifications - Irv Bromberg
Proposed Veten Tal Umatar Timing Modifications - Irv Bromberg
Frequency of Tevet 10 - Dr. Bernard Dickman
Abib 13, 14, and 15 - Vladimir Uvarov
Correctness of the Hebrew Year Count? Researcher A
Authors of the Hebrew Year Count? Researcher A
The Six Days of Hanukkah - Larry Padwa
Calculating Occurrence of Given Molad? - Dr. Bernard Dickman
The Lubavitcher Rebbe on Maimonides' Molad - Dr. B. Dickman
Explaining the Kalendis Method - Irv Bromberg
Online Lunar Phase and Molad Calculator - Irv Bromberg
Why the H in 5765H? - Rabbi David Seed
Why use the Julian Dates? - Rabbi David Seed
Kalendis Molad Adjustment Calculation Update - Irv Bromberg
The Molad and the First Day of the Month - Dr. Bernard Dickman
Torah Science vs. Secular Chronology - Yosef Gavriel Bechhofer
Search for a Sunrise Alarm Clock - Elizabeth Ranucci
Searching for Date Conversion Formulas - Yossi Yaffe
Request for Historical List of Passover Dates - Paul Moniodis
Request for Hebrew Year Number Transliteration - Giora Magen
Is Creation at AM 1 or AM 2? - Dr. John Stockton
What is the Real Purpose of the Dehiyyot? - Eli Nahmani
Why Are There So Many Hebrew Year Lengths? - Gregory C. David
Maimonides and the Length of the Seasons - Dr. Irving Bromberg
Shabbats of Three Torahs - Robert E. Heyman
Request for Remy Landau's Qualifications - William Jacobson
What is the Correct Day for Shabbat? - Donald Pullen
Hebrew Calendar PC Calculation Accuracies - Eli Nahmani
Request for Rain Web Site - Irv Bromberg
Hebrew Calendar Science and Myths - Shlomo Abrahams
The Molad Drift - Rachel Brown
When is Shmittah? - John Dekkers
Top Spiritual Site Award 2005 - Amy Lui
Why One and Two Days Rosh Hodesh? - Jack Gostl
Yaaqov Loewinger's Recent Article on 5765 - Ari Meir Brodsky
When Does the Hebrew Calendar Day Begin? - J.P. Mayer
Which Day Begins the Jewish Week? - Dr. John Stockton
Sefirat Ha'Omer Technique - Michael Koplow
Hindu Calendar - Shriramana Sharma
The 360-Day Year Calendar - Steve Winnitt
Yom HaAtzmaut's Moving Target Date - Ari Meir Brodsky
Babylonian Period Hebrew Calendar - Clark Wilkins
Plucking Harps and Calendar Cycles - Dwight Blevins
The Molad of Sivan 5765H - Noam Kaplan
Calculating the Molad of Tishrei 3790H - George Thlick
The Start of Tishrei in The Gregorian Year - Marshal Portnoy
Hanukah, December 25, and Hebrew Month Names - Marshal Portnoy
Hebrew Year Number Transliteration - KosherJava
Request for Historical Hebrew Calendar References - Lydia Esther
Free Hebrew Calendar Software for OUTLOOK - Dvir Gassner
Thank you!! - Ezra Lwowski
Blessing of the Sun..? - J. Neidich
The Significance of Enoch's Age? - Karmen Williams, Ed.D.
Next Hebrew New Year Start? - A. Zoltan Varga
Qeviyyot Like 5766H Between 5741H and 5752H - Morris Jesion
B'TU'TKPT and Rare Calendar Events - Ari Meir Brodsky
Date of Tisha b'Av 3830H? - Al Persohn
Date of Rosh HaShannah 5456H? - Lara Aase
Rare Calendrical Event for 5766H - Ari Meir Brodsky
Prime Numbers in the Hebrew Calendar? - Rabbi Steven S. Saltzman
Which are the Shabbat Days in America? - Kevin Kelly
Request for Lunar Calendar Algorithms - Cloves Santos, Brazil
The Rectified Hebrew Calendar - Dr. Irving Bromberg
Month of Abijah's Course? - Bernie Vlach
From: Patrick Greene
Date: Sun, 21 Nov 2004 14:59:38 -0800 (PST)
I would like to know how many months the calendar
had when Noah was alive. How many months short of our
present one was a single year.
thank you
Patrick Greene
---- Remy Landau replied:
Dear Patrick,
That is a very good historical question for a vast number of reasons.
No record exists of any calendar that may have been used by Noah, even
though the biblical text appears to be quite specific with regards to
the times of the flood, the ark voyage, the rains, and Noah's ages
before, at the time, and after the flood. For example, Noah was 600
years old when the floods began, the ark floated about for exactly 150
days, and so on...
Nevertheless, there is no specific answer yet known for your question.
The body of literature that has investigated this particular problem,
going back several centuries, remains largely speculative, and very
often tainted by subjective interpretations of the biblical text.
So in effect, your questions, excellent as they are, still remain
unanswered today.
Shavuah Tov!
Remy Landau
---- Patrick Greene replied:
Date: Mon, 22 Nov 2004
Dear Mr. Landau,
I want to thank you very much for your quick and informative reply.
Patrick Greene
Shannah Tovah!
Nachum Dershowitz
Date: Mon, 12 Sep 2005 03:35:56 -0700 (PDT)
==== Remy Landau replies
Thank you Nachum Dershowitz and Professor Halpern for the fascinating notes
you made in response to Ari Brodsky's questions.
Ari Brodsky also asked whether or not there are any Hebrew calendar events
rarer than Dehiyyah B'TU'TKPT.
This question will require significant qualification in order to be
properly understood.
For example, any molad of Tishrei occurs exactly either 3 or 4
times only in the full Hebrew calendar cycle of 689,472 years.
The 3-timers occur only for the 11th, 13th, and 15th years of the
mahzor qatan GUChADZT (ie, the fixed Hebrew calendar's 19-year cycle).
Clearly then, the frequency of each molad of Tishrei is therefore far
less than Dehiyyah B'TU'TKPT which occurs 3,712 times in the
full Hebrew calendar cycle of 689,472 years.
Are there any rarer events?
Assuming the improbable, which would allow Hebrew and Gregorian
calendar rules as known today to be fixed into a very large indefinite
future, then the following formal calculation can be made.
Due to the fact that both the Hebrew years and the Gregorian years
are of different lengths, the correspondence between the
Hebrew and Gregorian calendars repeats itself in a cycle of
14,389,970,112 Hebrew years, which is also
14,390,140,400 Gregorian years!
In other words, once in every 14,389,970,112 full and complete Hebrew
years, both the Hebrew and Gregorian calendars return to the
synchronization known at the start of that time period.
This is a very rare event indeed since the time span covered appears to
come very close to the age of the known universe.
I have heard from another correspondent, and will let others verify this fact,
that the Hebrew calendar to Easter cycle is several thousand times longer than this.
So it seems that the rarest Hebrew calendar event still has many
possibilities.
Shannah Tovah!
Remy Landau
From: Amos Alter
Date: Wed, 24 Nov 2004 14:52:21 -0600
While looking for something entirely different about calendars,
I came across your article. I have found it fascinating, and have
copied it to use some of the tables in my own calendrical doodlings.
May you live the longest possible version of 120 years!
(Of course, your 120-year cycle was determined the day you were born).
AA.
Date: Sun, 28 Nov 2004 09:23:23 -0800 (PST)
From: Jack Lipinsky, Ph.D.
Subject: Calendar Question
Hi Remy:
The Gemara in Talmud Tractate Ta'anit 29a says that Tisha B'av
in the year 70 CE when the Temple was destroyed fell on Motza'ei Shabbat
(the evening of the conclusion of Shabbat). Is this true???
Jack
Date: Sun, 28 Nov 2004 16:56:31 -0800 (PST)
---- Remy Landau replies
Dear Jack,
It is highly unlikely that any of the Amoraim would have
ever used a value of 70 ce for any year in their domain.
The ce (common era) year didn't come into being until the
4th century ce when it was set through the calculations of Dionysius Exiguus.
So we have to look at the clue of motzoei Shabbat... and work backwards
from there.
3830H would be the Hebrew year corresponding to the unknown 70 ce, by
formal calculation. For this Hebrew year, the Hebrew date Av 9 may be
determined to coincide with Shabbat.
Hence, we are noting that motzoei Shabbat would technically be the 10th
day of Av and not the 9th day, as implied by the Gemara.
But all is not quite lost. By one of these strange coincidences, it
must be noted that the 9th day of Av of the previous year, ie 69 ce or
3829H, coincided with Sunday. In other words, in the year 69 ce, Tisha
b'Av did indeed fall on Motzoei Shabbat, since the day began at
sundown, just as does the Motzoei Shabbat.
Your correspondence also underscores one of the great historical
debates that, to the best of my knowledge, appears to still have been
unresolved. In what year was the 2nd Temple destroyed? Wsa it 68, 69,
or 70 ce? If the Talmud passage to which you refer is to be believed,
then it appears that the Amoraim may have been sugggesting, by formal
calculation, that the year of the tragedy was 69 ce and not 70 ce. I
believe that Rambam, in Hilkhot Qiddush HaHodesh, leaves this matter
unresolved.
Shavuah Tov!
Remy Landau
Date: Sun, 28 Nov 2004 18:44:12 -0800 (PST)
From: Jack Lipinsky, Ph.D.
I suggest you read the page cited Taanit 29A very carefully,
as there are a number of historical issues.
Though I claim little historical expertise and no calendrical,
I will point out the following as worthy of your attention.
1. The Gemara finds itself difficult to deal with the disparity
in the calculation of when the first temple was destroyed based on
different dates given in Jeremiah and 2 Kings.
2. More to the point, the Rabbis certainly knew the date of the
destruction of the Second Temple as it was during their time period.
(thus argues the Meiri, and he is correct historically).
On the other hand, the Gemara has the Cohanim singing words from
the Psalm for Wednesday. Rashi claims that this is because
the words were a prophecy of doom on what would happen to the
Temple and were relevant to the destruction.
However, perhaps it is possible that the destruction took place in a year when
the 9th of Av fell on Wednesday. Might that suggest 68 or 69 CE?
This is not my area of expertise.
What is the debate over the dating of the destruction based? Certainly a great
deal is known about the reigns of Vespasian and Titus!
This is certainly a subject worthy of some investigation!
Indeed, the entire calculation of why Tisha B'av is a day of evil
is based on the Gemara's analysis of the incident of the spies' report,
which is traced to Tisha B'av (Taanit 29A) on the assumption that Tammuz
in that year had 30 days which is an issue I leave to you.
---- Remy Landau replies
Dear Jack,
Tanit @ 29a
""""
AND [THE TEMPLE WAS DESTROYED] THE SECOND TIME. (Gemara)
Whence do we know this? For it has been taught: Good things come to
pass on an auspicious day, and bad things on an unlucky day. It is
reported that the day on which the First Temple was destroyed was the
ninth of Av, A Sunday, and in a year following the Shmita. .... and
what Psalm did they recite? reference appears to be Psalm 94.
... The same thing too happened in the Second Temple.
""""
page 154 Soncino Translation (1938)
Technically, it is impossible to verify these facts simply because the
fixed Hebrew calendar did not exist then. In its place may have been a
highly elaborate, cumbersome and absolutely arcane methodology of
determining, and announcing, the starts of various months throughout
the year. This view comes from a simple reading of Tractate Rosh
HaShannah in which one notices that the Calendar Council was sometimes
torn apart by unbelievably acrimonious debate. (See for example RH
25a).
If one protracts the currently known calendar arithmetic to the
possible year in question, and it might be 3830H because that year is
close to the time of the Hurban and just happens to also be the year
following Shmita, then the weekday is Shabbat.
In other words, it is not Sunday as suggested by the text. Nor can it
be Motzoei Shabbat because that time would be Sunday 10 AV, and not 9
AV.
By formal calculations, the previous year, 3829H, finds the 9th Av on
Sunday. But that year, according to current rabbinic theory, would have
been the year of Shmita, and not the year following Shmita, as
suggested by the Gemara.
So here we have the basis for an argument in support of the idea that
the calendar methodology of the Mishnah was decidedly different than
our currently accepted fixed Hebrew calendar method. Otherwise, it is
impossible to resolve the contradictions found by calculation.
Consequently, in answer to your question, it would be reasonable to
defer to the documented testimony of the Gemara as found in Tanit 29a.
Shavuah Tov!
Remy Landau
Date: Mon, 29 Nov 2004 20:55:09 -0800 (PST)
From: Jack Lipinsky, Ph.D.
Remy:
Before I do my own investigation, is Josephus not reliable on the date?
After all, he was there and certainly knew the date. Is it not possible
that the Rabbis fudged the date so that the destruction day of both
Batei Mikdash would coincide. A careful reading of Taanit suggests this.
As well, I am very familiar with the opening Gemara in Megilla
and you are absolutely right about the change in calendrical
calculation somewhere in this period during the compilation
of the Talmud. This may well be the "fixed calendar" of Hillel II.
Jack
Date: Tue, 30 Nov 2004 04:07:30 -0800 (PST)
---- Remy Landau replies
Dear Jack,
Please excuse my discomfort in having to comment on what remains highly
speculative conjecture. But until archeological, and/or, historical
evidence is discovered, the many questions and comments which you
present will have to remain in the domain of scholarly speculation.
Therefore, no conclusion can be derived in this discussion, even if a
statement of agreement can be reached on a matter of speculation.
Permit me to explain below....vvvvvv
> Remy:
>
> before I do my own investigation, is Josephus not reliable on the
> date? After all, he was there and certainly knew the date.
Josephus was brought up in prior discussion. As a disciplined
historian, he should have been in some position to establish a
particular date for the event. However, to establish the dating of
particular historical events, Josephus might also have been using data
and interpretations different than those used by the Amoraim. This
therefore would have led to different dates for the same events. This
too is the case with many other contemporary events in other religions.
> Is it not
> possible that the Rabbis fudged the date so that the destruction day
> of both Batei Mikdash would coincide. A careful reading of Taanit
> suggests this.
The reading suggests that 9 Av as the time of the destruction occurred
on a Sunday AND in the year after Shmita. It is actually impossible to
confirm whether this indeed did happen about 656 years earlier on the
day of the First Temple's destruction. It is even less than possible to
determine the basis on which the Amoraim actually relied to make that
particular observation. So it is impossible to know what to say in this
situation.
> As well, I am very familiar with the opening Gemara in
> Megilla and you are absolutely right about the change in calendrical
> calculation somewhere in this period during the compilation of the
> Talmud. This may well be the "fixed calendar" of Hillel II.
The more one looks into the history of Hillel II's contribution to the
fixed Hebrew calendar, the less contribution to the calendar one can
attribute to this particular figure of history. Historians continually
appear to uncovering differences that lead to a fixed calendar
somewhere after the mid-9th century, and the beginning of the 10th
century. You might want to read Sacha Stern's *Calendar and Community*
(Oxford Press 2002) for more historical detail.
Best Regards
Remy Landau
Date: Thu, 2 Dec 2004 01:41:47 -0500
From: Ari Meir Brodsky
Outside of Eretz Yisrael our daily prayers should include
the request for rain, beginning with the Maariv service this coming
Saturday evening, December 4, 2004, corresponding to Motzei Shabbat,
22 Kislev, 5765.
The phrase "Veten tal umatar livrakha" is inserted into the 9th brakha
of the weekday shemone esrei, from now until Pesach.
The request for rain is begun in the Diaspora on the 60th day
following the fall equinox, as calculated according to the
approximation of Shmuel in the Talmud.
If you are interested in more information about this calculation,
you may wish to follow the link below, to a fascinating
article giving a (very brief) introduction to the Jewish calendar,
followed by a detailed discussion on why the prayer for rain begins
when it does.
Thanks to Russell Levy for bringing this article to my attention last year:
http://lookstein.org/articles/veten_tal.htm
If you're interested in reading more about the Jewish calendar,
don't forget about my essay, "How is this year different from all other
years?" It doesn't say anything about the prayer for rain, but it does
include many other calendrical curiosities, such as the fact that the
first day of Hanukkah can fall on any day of the week except for Tuesday:
http://individual.utoronto.ca/aribrodsky/
Wishing everyone a happy Hanukkah!
Ari Brodsky.
Date: Wed, 1 Dec 2004 16:57:30 -0700
From: Dwight Blevins
Remy,
Thought this was interesting. Remember all the mathematical patterns
of calculation which generate the 71/176 split of the 247 year cycles?
For instance, the cluster patterns of the 7-7-3-7-7 Tishrei 1
declarations, which fell at 1999g, also had a hit 71 years earlier in
1928g. I've come across this 71 year phenomena many time in the 247
year patterns. If I recall correctly the frequency of the 6942 period
also have a 71 year artifact at times. The frequency of some of the
rules of postponement might also display similar patterns within the
247 year circles. There are, of course others, of which 71 years is
one of note.
So what? Well, I came across this and thought the similarity of
coincidence was striking. Click here and you'll see how my leaping
thoughts generate another possible myth of connection (ie, as to the 71
patterns) between pure mathematics and something else.
http://www.israelnationalnews.com/news.php3?id=70349
Of course, with a little more stirring of the brew, there is
also the question of the 176 slice of the 71 + 176 = 247. Of what
mystic coincidence is that? Well, 176 is the number of verses of the
22 sets of 8, contained in the Psalm 119, and is also the symmetrical
frequency of the 6th diatonic, 3rd octave musical note F, which by
number (6) of the scale is also the week day of preparation.
Why do you think the Sanhedrin employes 71 seats?
Is that a throw back to the 70 elders + the seat of Moses, or 70 elders
+ the High Priest, Aaron? Or, just a random number based on the
accidents of politics and religion?
Dwight Blevins
Date: Tue, 07 Dec 2004 11:24:11 -0500
From: Larry Padwa
Subject: Extension of Questions 143 and 145
Hi Remy,
The archives of the Weekly Questions are extremely interesting. On
occasion, reviewing old questions can suggest related new ones, as in
the following instance.
In questions 143 and 145, you and your correspondents discuss the
questions of the smallest span of years containing all six possible
year
lengths (6), and the largest span of years not containing all six
possible year lengths (43).
A pair of related questions is to identify the smallest span of years
containing all fourteen Keviot, and the largest span not containing all
fourteen Keviot.
Unlike question 143 where it was possible to find spans of six years
containing all six year lengths, it is impossible to find a span of
fourteen years containing all fourteen Keviot. The reason for this is
that the fourteen Keviot contain seven leap years, and the smallest
span
containing seven leap years is a span of seventeen years. Thus the
answer to the first part of my question is at least seventeen, but
might
be larger.
I haven't done any further analysis on this, nor have I applied
exhaustive searches to find the answers. Do you (or any of your
correspondents) have any further insight into any of this?
Happy Chanukah,
-Larry
Date: Tue, 7 Dec 2004 13:18:25 -0500
From: Pete Ryder
Subject: WOW!
My thoughts on your article re the Hebrew calendar are that I'm very impressed
at the complexity of the system. Your analysis really involves only simple
arithmetic, but it certainly shows how complicated things can get.
I appreciated learning about it, but didn't get my question answered,
"How long is a Hebrew month?" Obviously, just like the Gregorian months,
it varies.
Is there a table on the months and their lengths? Apparently, the lengths can
vary due to the postponement rules.
Thanks very much for your analysis.
Date: Tue, 7 Dec 2004 10:43:06 -0800 (PST)
---- Remy Landau replies
Dear Peter,
Thank you so much for the encouraging words!
On the length of any Hebrew month in the fixed calendar...
The lunar month,
- the period from new moon to new moon is fixed at the average value of
29 days, 12 hours, and 793 halaqim (793 / 1080 hour)
- each calendar month alternates exactly between 29 and 30 days...
except for the months Heshvan and Kislev which can both be either 29 or
30 days.
- 7 times in every 19 Hebrew years an extra month of 30 days is added to
the year.
That's about it on the length of the Hebrew months.
Hag Urim Sameach!
Remy Landau
Date: Mon, 20 Dec 2004 03:59:18 +0000
From: Researcher A
Subject: Origin of the Hebrew Year Count?
dear mr landau
I have just read your introduction to the Properties of Hebrew year periods online,
which i found fascinating.
I am sorry to take up your time, but can I please just ask if you know exactly where
and when the idea and the official adoption took place of the actual numbering
of the hebrew year; someone somewhere must one day have announced the number of
the official year.
It seems that this was not done in the bible period, nor that of the Hasmoneans
immediately afterwards; i presume that after the Roman expulsion of the Jews
there was no attempt to put a number to the year and neither is it apparent
during the Babylonian Talmud period thereafter.
Can it be that this dating of the years is a relatively late custom, from the
middle ages?
I am sorry if I am asking something that is common knowledge, but it is as
yet unknown by me and I am curious about our history.
With Kind Regards
Researcher A
Date: Mon, 20 Dec 2004 18:17:58 -0800 (PST)
---- Remy Landau replies
Dear Researcher A
To the best of my knowledge there is no real answer to this fascinating
question.
Invariably, the year counts begin with some biblical event, such as the
Bereshit (ie, Genesis, Creation) and attempt to deduce the number of
annual circuits by means of the textual references. The problems begin
when it is noted that the biblical record is discontinuous, and
requires that some time line gaps be deduced. Different schools have
come to different conclusions simply because the numbers chosen have
pretty much depended on the particular philosophies of these schools.
The Hebrew year count may have been established as early as the 2nd
century... in a work known as *Seder Olam*.
Of course, this particular count has seen its challengers... but in any
case, the current Hebrew year count is about as good a year count as
any. So there is very little point in suggesting that it might be
something else since nothing real would be gained.
Should you be interested, you can actually find a number of very
interesting web resources on *Seder Olam* and the year count using the
Google search engine.
Shavuah Tov!
Remy Landau
Date: Wed, 22 Dec 2004 00:39:43 -0500
From: Irv Bromberg
Subject: Proposed Hebrew Calendar Modifications
I have been very busy working on calendar stuff even though I haven't
bugged you much.
As it happens, this evening I posted a major update of "Kalendis" on my
web site, supporting the new Symmetry454 Calendar (without "Irvember",
in leap years December simply has 5 weeks), and introducing my new
ultra-long-term accuracy Mean Orbital Year leap rule.
On the Hebrew Calendar side I've been studying the original Hebrew
version of Maimonides' Kiddush haChodesh with Rabbi Moshe Ginz after
reading the English translation on my own, and I hope to implement
Maimonides' calculations as computer functions for comparison with
modern astronomical algorithms.
I am also continuing to analyze the more accurate leap rule, having
recently posted a 353-year cycle proposal. I am now certain that
Feldman's method was defective and incomplete, in that it is not
possible to change the Hebrew calendar leap cycle without thoroughly
evaluating the interaction with Rosh Hashanah postponements. I have
now learned that it is possible, although obviously not desirable
(because of ritual inconvenience), to design a Hebrew calendar leap
cycle that does not need ANY postponements. The use of continued
fractions for this is NOT appropriate because the leap month does not
equal the length of the mean lunations and also because left over days
have to add up to a suitable number of postponements. (In addition the
target lengths that he used for the so-called "tropical year" and
synodic month were insufficiently accurate, and that is why his
continued fraction landed at 334 years instead of 353.) I will sort
project out soon, im yirtzeh ha-shem, but first I have to finish
documenting the updated Symmetry454 arithmetic and posting the new math
for the Mean Orbital Year. I expect that the combination of my
expressions that track the Mean Synodic Month together with the Mean
Orbital Year will constitute the basis for a future Hebrew Calendar
reform idea, that of a calendar that indefinitely tracks these without
complicated astronomical algorithms, the main hitch being maintaining
as a minimum the Rosh Hashanah postponements that are ritually
convenient.
I made a web page about postponements but it is not posted yet because
I feel that my thesis is too weak at this point...
Did you notice my proposed lunar probe space program? Tongue-in-cheek,
of course, but see what you think -- it would solve a lot of problems
of the past...
http://individual.utoronto.ca/kalendis/hebrew.htm#probe
(looking for somebody with a few spare billion dollars...)
Attached, is a little blurb that I recently wrote
about Sh'ela for publication at my web site. It is not posted yet, I
would appreciate your feedback.
-- Irv
Attachment
Proposal for adjusting when the phrase VeTen Tal U-Matar
(request for rain, Sh'ela) should be said in the Amidah prayer
by Dr. Irv Bromberg, University of Toronto, Canada
For a more detailed analysis of Sh'ela see VeTen Tal U-Matar at
http://www.lookstein.org/articles/veten_tal.htm
by Professor Dr. Moshe Sokolow of Yeshiva University. Herein I will only briefly outline the main points and then jump to my proposed resolution of this issue.
Please note that I have no rabbinical training and no authority to propose
anything in this regard, just an interest in calendars, astronomy, and Israel,
a lot of nerve and hopefully some good common sense.
As a Canadian living in a cool climate with rain (or snow) all year round,
the timing of all prayers with regard to rain and dew seemed meaningless to me
until I spent a year living in Israel in 1977. Then at last I realized
that those prayers perfectly suit the climate in Israel. When Israel prays
for rain, the rains come. When Israel prays for dew, the rains stop.
Since then I always say those prayers with the Land of Israel in mind,
not the local weather conditions.
One might expect that Sh'ela should begin after the official prayer for
rain during the Musaf service on Shemini Atzeret. However, the ancient
sages delayed Sh'ela for 11 days until the 3rd of Cheshvan, to allow time
for pilgrims to return home after Sukkot. Subsequently Rabban Gamliel extended
the delay to the 7th of Cheshvan, to allow 15 days "for even the tardiest
Israelite to reach the Euphrates". Their concern was that rain would turn
the roads to mud before the pilgrims reach their homes.
Later, for those living in lands outside Israel, originally codified by
Maimonides as applying to Mesopotamia, Syria, Egypt, and "nearby or similar
places", the delay was extended to 60 days after Tekufat Tishrei, a term that
is loosely translated as the autumnal equinox. The Talmud in tractate Eruvin
on page 46 very briefly mentions that on Tekufat Tishrei and on Tekufat Nisan
the Sun rises at the middle of the range of sunrise points during the year
and sets at the middle of the range of sunset points.
This definition is astronomically quite correct, within a day of the actual
equinox, but it is for observational purposes and doesn't yield a method
for computing the date of any equinox. More precisely, the Sun would rise
exactly due East only if the equinox occurred at the moment of sunrise,
likewise it would set exactly due West only if the equinox occurred at the
moment of sunset.
Obviously it can never do both on the same day, it rarely does either,
and when the equinox coincides with either sunrise or sunset it only does so
for one meridian of longitude!
On the other hand, for every equinox there is always exactly one meridian
of longitude somewhere on Earth that sees sunrise at the moment of the equinox,
and exactly one other meridian elsewhere (one day span to the East) that sees
sunset at the moment of the equinox.
Also note that on the date of the equinoxes the Sun rises almost due East
and sets almost due West as seen from everywhere on planet Earth,
even beyond the Arctic and Antarctic Circles (except the poles, at which the
only direction is towards the opposite pole).
The English word "equinox" comes from the Latin for "equal night",
because the duration of daytime and night time are approximately equal on
the date of the equinox. Due to atmospheric refraction, the Sun near the
horizon always appears to be at a higher altitude than it really is, so
daytime at the equinox is always longer than night time. For example, at
Jerusalem on the autumnal equinox in the Hebrew year 5765 the daytime was
12 hours and 17 minutes, whereas the night time was 11 hours and 42 minutes
(this doesn't add up to exactly 24 hours because the seconds were rounded
as they are insignificant and because it is already changing for the next day),
so the day is 35 minutes longer than the night (these times vary plus or minus
a 1-2 minutes).
The calculation of the date to start Sh'ela is based on Amora Shemuel,
who assumed that the four Tekufot (seasons) are equal in length
(astronomically they are not equal), each of 91 and
5/16 days = 91 days 7 1/2 hours.
With four equal seasons the year was taken to be exactly
365 1/4 = 365.25 days long, which is the same as the mean length of the
Julian Calendar year. The actual equinoctial year length is slightly
shorter, currently the mean vernal equinoctial year is 365.242362 days,
even shorter than the mean Gregorian Calendar year length of 365.2425 days.
Thus according to the calculation of Shemuel the Tekufat Tishrei drifts about
3 days later with respect to the true equinox for each elapsed 400 years.
Today it is about 13 days late, for essentially the same reason that the
Julian Calendar is 13 days behind the Gregorian Calendar. However the
Gregorian Calendar itself has drifted almost 1 1/2 days late with respect
to the equinox, so today Tekufat Tishrei is almost 14 1/2 days late with
respect to the actual astronomical boreal autumnal equinox, and during the
21st century it will continue to be delayed further at a fairly steady rate
averaging 11 minutes 33 seconds later per year.
The later that Sh'ela is calculated to start, the worse it is for the
Land of Israel.
Today we are not concerned about the roads getting muddy because of rain,
for the roads are paved throughout Israel. Anybody who walks to Jerusalem
for Sukkot (as my wife and I did in 1977) surely will return by some sort
of vehicle. Pilgrims from outside Israel arrive and depart by airplane.
The population of Israel is much greater than it has ever been at any prior
time in history, so the need for water (rain) is greater than it has ever
been before.
This is not a matter to be taken lightly or to be allowed to wallow in debates
over this or that rabbinical opinion. Why squander the power of prayer?
Consequently it makes no sense to delay saying Sh'ela at all, rather
I submit that:
Sh'ela ought to commence immediately after Shemini Atzeret for everybody,
everywhere.
It is vital that Israel get the precious water that she needs, and everybody
should use every potential opportunity to ask for rain.
By the word "potential" I am implying that there is no point in asking
for rain when it is inconceivable that the request may be granted.
That is why the prayer is not said all year round. There is a standing
consensus that rain is not requested during Israel's summer time because
it "just ain't gonna rain".
What about people living in climates that have rain at other times,
or when rain would be harmful, or that live in the Southern Hemisphere, etc.?
In contradiction of the 17th century ruling of Rabbi Chaim Shabbetai of Salonica,
I propose the following:
Everybody, everywhere should say Sh'ela at the same time as Israel, but
those outside Israel should say the prayer with the Land of Israel in mind.
One simple, sensible rule for all, without erroneous equinox calculations.
Pray together for Israel — what is good for the Land of Israel is good for
all of Am Yisrael.
This page updated Tevet 8, 5765
= December 21, 2004 (Symmetry 454)
= December 19, 2004 (Gregorian)
Date: Wed, 22 Dec 2004 17:03:53 EST
From: Dr. Bernard Dickman
Subject: Frequency of Teves 10
Hi:
Asara B'Teves rarely occurs on a Wednesday (only possible in a leap year).
The last time was 1981 but it will occur again in 2008.
That should mean that Rosh Chodesh Teves rarely occurs on a Monday.
Your tables seem to indicate otherwise.
Dr. B. Dickman
Date: Wed, 22 Dec 2004 14:58:53 -0800 (PST)
---- Remy Landau replies
Dear Bernard,
The tables to which you might be referring indicate that the 10th day
of Tevet occurs 26,677 times in the full Hebrew calendar cycle of
689,472 years. That's about 3.8% of all of the possibilities.
This correlates to your observations regarding the rarity of a
Wednesday fall for Tevet 10. It also correlates remarkably well to the fact that
the 10th day of Tevet occurs on Wednesday only if the year is a 383-day year
begun on Thursday. (See The Qeviyyot).
The current Hebrew year 5765H is a 383-day year begun on Thursday.
However, you have to distinguish between the first day of the month and
the first day of Rosh Hodesh since Rosh Hodesh is sometimes two days
long. For the month of Tevet, it is always a one day Rosh Hodesh in
deficient years (ie, the years in which both Heshvan and Kislev are 29
days long), while it is two days long in the other qeviyyot.
Consequently, you must look at the tables which relate to the 1st day
of the month (See The First Day of The Month),
and base the calculations of the Tevet 10 date from those statistics.
This was done above.
Once that is done, I believe that the difficulty you appear to have
experienced disappears.
Best Wishes for the coming year of 2005g!
Remy Landau
Date: Thu, 23 Dec 2004 13:45:30 +0100 (CET)
From: Vladimir Uvarov
Subject: Abib and Nisan 13, 14, 15
Dear Mr. Remy Landau,
I read your articles about calendars with the great interest. Could
you please answer to my question about the Jewish calendar?
In ancient Jewish calendar the new month began when the moon
crescent was visible, and the new day began with sunset. According to
E.J. Bickerman (Chronology of the Ancient World, London, 1969) the time
interval between the moon conjunction and the first visible crescent
in Babylon in March is about of 16 h 30 m. It is easy to calculate that
the average astronomical full moon occurs on the 14th day of Abib in
the morning.
Comparing the Passover dates in the presently known fixed Jewish
calendar with the instants of the real astronomical full moon, one can
see that the average astronomical full moon occurs on the 15th day of Nisan
in the morning.
Therefore, it can be concluded that "Abib 14th" = "Nisan 15th". Is
it true? In the present Jewish calendar the Passover is celebrated in the
night from 14th to 15th of Nisan. But when the Passover was celebrated in the
ancient Jewish calendar? What means the phrase "on the fourteenth day of the
month at even" (Leviticus 23:5)? Does it tell about the night from 13th to 14th
of Abib, because the day begins with evening, according to "and there was
evening and there was morning, one day" (Genesis 1:5).
Sincerely Yours,
Vladimir Uvarov
Date: Thu, 23 Dec 2004 08:56:07 -0800 (PST)
---- Remy Landau replies
Dear Vladimir,
You have certainly well researched the astronomy of this subject.
The findings of E.J. Bickerman, as cited are certainly fascinating.
Another work on the Baylonian calendric system which appears to still
be quoted is the *Babylonian Chronology* by Parker and Dubberstein,
originally published in 1942.
However, when you say that
> It is easy to calculate that the average astronomical
> full moon occurs on the 14th day of Abib in the morning.
you are speaking of a highly theoretical mathematical construct and a
formidable assumption concerning what is really meant by the month of
Aviv... neither of which necessarily reflect any particular historical
reality.
In the first instance, the use of current mathematical techniques to
track the progress of the moon, or for that matter, any particular day
in any particular calendar, imposes possibly non-existent constraints
on what the ancient societies might themselves have done to bring into
harmony the sun, the moon, and the rather undeveloped, but emerging,
digital arithmetic of the times.
The Metonic cycle needed the 18th century mathematical genius Carl
Friedrich Gauss to be fully unravelled.
In the second instant, it is not clear that the month of Aviv was
indeed perfectly coincident with the latterly named month Nisan. There
are considerable Talmudic passages which tend to force the month of
Aviv onto the month of Nisan. However, these passages are more dogmatic
than conclusive. But not to upset the collective wisdom of the scholars
that put together the pages of the Talmud, Nisan is formally believed
to be Aviv, regardless of whether or not that is indeed factual
history.
> Comparing the Passover dates in the presently known fixed Jewish
> calendar with the instants of the real astronomical full moon, one
> can see that the average astronomical full moon occurs on the 15th
> day of Nisan in the morning.
>
> Therefore, it can be concluded that "Abib 14th" = "Nisan 15th".
> Is it true?
One of the first questions that I would ask is how far into the past
can you really compare the Pesach dates of the presently fixed Hebrew
calendar with the supposedly *real astronomical full moon*?
This is being asked because the presently known fixed Hebrew calendar
does not appear to go very much farther back than the mid-9th century
ce. Also, what does anyone really mean by *real astronomical full
moon*, and how far back into history will that concept of the full moon
really exist?
Consequently, logic based on these kinds of ideas is formal and must be
considered massively speculative in its conclusions.
I'm not really able to understand the ideas of the full moon linked to
the festival of Pesach as implied, not only by yourself, but by a
significant number of very serious scholars in related disciplines. The
occurrence of Pesach and the full moon has never been shown, to the
best of my knowledge, in any biblical regulation linking these two
events. In other words, not a single biblical regulation, nor for that
matter, Talmudic requirement I believe, requires that Pesach be
observed at or near the presence of a full moon. Consequently, the
existence of the full moon does not bring about the existence of Pesach
and vice versa. However, it is interesting to see today, that a full
moon is an event that takes place during Pesach, just as it is
interesting to see today that the new moon is an event that takes place
during Hanukkah.
Finally, you seem to be having a bit of difficulty with an idea that is
very easily understood by the Jewish world.
> What means the phrase "on the fourteenth day of the
> month at even" (Leviticus 23:5)? Does it tell about the night from
> 13th to 14th of Abib, because the day begins with evening, according
> to "and there was evening and there was morning, one day"
> (Genesis > 1:5).
The Jewish days all begin at sunset, and end at sunset... unlike the
civilian days which all begin at midnight and end at midnight.
Thus, Shabbat begins at about sunset, and the observant light the
Shabbat candles just a bit before sunset. The same applies to any
other day in the Hebrew calendar. Thus, once the sun had set on the
14th day of the month, it was automatically the start of the 15th day
of the month. By the way, the biblical text is referring to the
twilight of the 14th, and if followed, it states *and at night* which
of course is now the 15th.
These are some of the reasons why I would be reluctant to either agree
or disagree with what you have suggested above.
Happy New Year 2005g!
Remy Landau
Date: Tue, 28 Dec 2004 05:30:27 +0000
From: Researcher A
Subject: Correctness of the Hebrew Year Count?
Dear Mr Landau
Thank you very much for the courtesy of your reply; I was trying
to understand when the present count 5765 actually began and as you
rightly say, it appears to have been set when Hillel II attempted, some
1,800 years ago, to use the bible as a counting guide, using generations
and rules of differing kings.
Of course this is a fallible process although neither his methodology,
nor his results, seem to have been doubted and therefore we as a people
can date our "universal hebrew calendar" from that time.
But this leads to another, local difficulty, which perhaps you can help with.
The Torah talks of a sabbath year for the Land (of Israel) when it was to be left
to lie fallow and not to be worked; in addition there are to be jubilee years
every fifty years, affecting property and servants.
The question is this; can we presume that the first "seventh" year and the
first "fiftieth" year were to be counted from the first year that the conquest
of Canaan began under Joshua?
Apart from the problems that the Land was not all conquered for many years
(some 400 years in the case of Jerusalem, for example), if the sabbath and
jubilee years were kept - and therefore counted, from one to the next - does
this not suggest that an accurate record of the number of years since
Joshua's conquest began, would have been kept?
Perhaps the answer to this question, like so many others, was lost with the
Temple almost 800 years after Joshua.
Looked at the from the perspective of history, some 1,800 years after
Hillel II, and more than 2,500 years since presumably all accurate dating
records were lost, it seems that this present date of 5765 is totally
uncorroboratable and is probably the culmination of wishful studying by a man
who could not have been in possession of all the necessary facts.
The only historical point of interest which scientifically coincides with events
5765 ago is this; that was approximately the chalcolithic period in the Near East
and of all the archaeological evidence revealed beneath Jerusalem so far, the
oldest remains are dated to approx 5,500 years ago. This is also the date, roughly,
of possible narrations of large floods in the region, written in other cultures.
So although Hillel II did date his calendar to a biblical event, perhaps he was
just being a little optimistic with the moment of the Creation of the world
(the dinosaur egg in my pocket confirms he got this date a little wrong), but
what about a Flood, or a Tsunami something like that?
Noah's epoch seems a much more logical candidate for 5765 years ago; especially
since we know that Abraham lived about 4,200 years ago and if there really were
just ten generations, as is written, between the two men, probably about
1,500 years is as big a gap as feasible.
It doesn't make Hillel right, but unwittingly it may make him lucky!
A great pity that all the national records were lost though, is it not?
Best wishes
Hugh
Date: Tue, 28 Dec 2004
---- Remy Landau replies
Dear Hugh,
Your researches into this subject is breathtaking in its scope.
You are quite correct in concluding that we do not have any real records of
history to either confirm or deny the 5765 years from Bereshit.
However, Hillel II was not responsible for the year count. Nor is it clear
from historical research precisely what was Hillel II's contribution to the
Hebrew calendar.
As far as the dinosaur egg is concerned, the modern rabbinic thinking on this
is that none of us really know what is meant by *one day* or *one year* in terms
of the biblical text. These phrases could refer to time spans in the thousands,
millions or even billions of years in the eyes of the Omnipresent. That is good
enough for now.
So, 5765 is as good as any as the basis for any year count.
Happy New Year 2005g!
Remy Landau
Date: Wed, 29 Dec 2004 02:38:01 +0000
From: Researcher A
Subject: Authors of the Hebrew Year Count?
Dear Mr Landau
Thank you again for your letter; I feel guilty for taking up your time this way.
I did not know Hillel II (not the Elder) was not the progenitor of the
universal Hebrew calendar; I thought he was!
My interest in wanting to know when the calendar dates back to arose last
(Hebrew) month during Chanukah, when i read the first Book of Maccabees,
to understand the actual story of Chanukah, not the dreidel and doughnut
and oil jar nonsense we were fed as kids.
The story is dark and bloody and all the more glorious for that, but what
caught my attention was the dating.
I Macc ch 4 relates the liberation, purification and rededication of the temple,
with the date given as 25 kislev in the year 148.
This year refers to the age of the Seleucid empire, established by
Alexander The Great's general Seleucus in 312 BCE.
148 years from that date would be 164 BCE, which equates (today) to the
Hebrew year 3597, the year generally recognised by jews as the year of
Chanukah. Thus Chanukah took place 2,168 years ago.
So my question remains, when did we start dating years in this universalist way?
It must have been after the Hasmoneans, as it was an official Hasmonean
historian who wrote the Book of Maccabees and the dating is clearly Hellenist.
Was it after Herod the Great? There is no reference in any biography of that
Idumean of universal Hebrew time.
Between Herod and Bar Kosiba was nothing but the Pax Romana, where surely
Hebrew dating would not have been recorded.
The reconstruction of the temple by Herod (in effect the third temple) was not
given a Hebrew date, although we know that Herod conquered Jerusalem in 37 BCE
(from Antigonus, last of the Hasmoneans), constructed his palace 14 years later
in 23 BCE and finally completed the new Temple mount and dedicated the new
Sanctuary in 10 BCE.
Thus we come to the period immediately (ie within 100 years) after the
expulsion, mainly in Babylon, which bring us, at length and with some regret,
into contact with the Rabbis...
How can we find out who started counting backwards?
With best wishes
Researcher A
Date: Tue, 28 Dec 2004 19:10:15 -0800 (PST)
---- Remy Landau replies
Dear Researcher A
We can't... or at least not until some archeological material is
recovered which will definitively answer your questions.
Happy New Year 2005g!
Remy Landau
Date: Fri, 24 Dec 2004 14:44:36 -0500
From: Larry Padwa
Subject: The Six Days of Hanukkah
Hi Remy,
A couple of more Tevet and 2005 trivia items (which are truly trivial
and border on the silly):
1)Next year (2005) we will not have 10-Tevet.
2)Next year we will have only six days of Chanukah!
Shabbat Shalom,
Happy New Year
-Larry
Date: Thu, 30 Dec 2004 16:01:40 EST
From: Dr. Bernard Dickman
Subject: Calculating Occurrence of Given Molad?
Dear Remy:
Is there anyway to calculate when a specific molad occurred?
Let me suggest that you include discussions of Tekufahs to your website.
Thanks for your very useful and informative website.
Dr. Bernard Dickman
Date: Thu, 30 Dec 2004 15:38:04 -0800 (PST)
---- Remy Landau replies
Dear Bernard,
The reason it is not possible to actually know when exactly a
particular molad occurred is that the same molad ocurs 47 times in the
full Hebrew calendar cycle of 689,472 years.
The Tishrei moladot can occur either 3 or 4 times in that full cycle.
So the fact that a molad has a particular value does not provide any
clue as to which molad it really is.
These ideas are documented in the Weekly Question Archive,
at questions 12, 13, 68, 69, 71, and 115.
The dates for any given molad easily can be found through simple
computer programs in the programming language of your choice.
With regards to the Tequfot calculations, it's an interesting
suggestion which probably might be acted on some time in the future.
Happy New Year 2005g!
Remy Landau
Date: Thu, 30 Dec 2004 19:21:45 EST
From: Dr. Bernard Dickman
Subject: The Lubavitcher Rebbe on Maimonides' Molad
Dear Remy:
Thanks for your response. Since it takes 181,440 months for every possible molad
to occur, some possible molads have never occurred and others have occurred
exactly once. I am trying to find if and when a particular molad occurred.
The basis for my question is that Rambam mentions a particular molad in
Hilchos Kiddush Hachodesh (6:7).
The Lubavitcher Rebbi (Sichos, volume 21, Rosh Chodesh Tammuz 5744) states
that this molad was not arbitrarily chosen but must be the molad when
Rambam was writing.
A quick check has not yet found this molad. I wanted to see if this molad
was significant for some other reason.
Dr. Bernard Dickman
Date: Fri, 31 Dec 2004 08:24:17 -0800 (PST)
---- Remy Landau replies
Dear Bernard,
Often cited as the repetition of the law, Maimonides' 14 volume work
called *Mishneh Torah* was compiled over a 10 year period towards the
latter end of the 12th century. The 3rd volume of this religious legal
compendium includes *Hilkhot Qiddush HaHodesh*, which is a
documentation of the rules and regulations governing the organization
of the Hebrew calendar.
In order to explain the actual calculation of the moladot, chapter 6:7
of *Hilkhot Qiddush HaHodesh* begins with an example of a molad of
Nisan set to 1d 17h 107p. Such a molad, of course, leads to a molad of
Iyar that is 3d 5h 900p.
Theoretically, this particular molad of Nisan will first occur for Nisan
38,058H on Sun 14 Aug 34,298g.
Shabbat Shalom!
Remy Landau
Date: Fri, 24 Dec 2004 14:48:58 -0500
From: Irv Bromberg
Subject: Explaining the Kalendis Method
... I updated my "Symmetry454 FAQs" PDF document, adding answers
to the following questions:
- Isn't it rather radical to have 5 weeks (35 days) in every 3rd month?
- How accurate is the Symmetry454 Calendar? How does it vary with
seasons?
- Won't the insertion of the Leap Week be disruptive to businesses,
etc.?
The updated FAQs PDF is at:
http://individual.utoronto.ca/kalendis/Symmetry454_Calendar_FAQs.pdf
My main "competition" in the Gregorian Calendar Reform world is Dr.
Richard Henry, an astronomer at Johns Hopkins. He is the one that
drummed up all this interest by issuing a press release. When he
couldn't stand all the sudden media attention he diverted some of it to
myself, and others. He also has a leap week perpetual calendar, but
his month lengths are 30-30-31 days, and his leap week is dubbed
"Newton" and inserted between June and July. My Symmetry454 has month
lengths of 4-5-4 weeks, and the leap week has no name because it is
simply appended to December in leap years.
In the past my "Classic" Symmetry Calendar had month lengths of
30-31-30 days and the leap week was separate at the end of the year,
dubbed "Irvember", a name that was invented by a family member
ridiculing my calendar at the Passover sedar last year, to the great
delight of all present. With Henry's Calendar in mind, I was later
inspired to call my leap week "Einstein", especially because Symmetry
was an essential part of the mathematical derivation of the Theory of
Relativity, but after switching to the 4-5-4 week configuration there
was no need for a stand-alone name. Meanwhile, I was astonished to see
that at Henry's web site he is himself dissatisfied with his choice of
"Newton" and he is having a contest to come up with a better name, and,
get this, he has put forth "Irvember" for his personal vote! I can't
tell how serious he is about that...
Regards, Irv.
Date: Mon, 3 Jan 2005 11:24:13 -0500
From: Irv Bromberg
Subject: Online Lunar Phase and Molad Calculator
In my freeware "Kalendis" program, which you can download from my web
site, is a feature accessible through the menu path File --> Export -->
Hebrew --> Moladot for Year.
It lists all of the moladot for the Hebrew year that is presently
displayed in the Hebrew calendar window, but in addition to the
expected traditional information it shows the moment of the actual
lunar conjunction, relative to the announced molad time and it shows my
proposed adjustment to bring the traditional molad to the true mean
lunar conjunction. In addition, if you go to that day in Kalendis you
can see the lunar phase at any desired time. The fixed day number in
the Time and Astronomy window is the number of days elapsed since the
epoch of the Gregorian / ISO / Symmetry454 Calendars. If it has no
decimals then it refers to 00:00h UT. If you make it have .5 as a
decimal then it refers to 12:00h UT, etc., and as you change it you can
see the effect on the solar longitude and lunar phase that is displayed
in that window. In addition, the "Events" window shows the actual UT
time of the lunar conjunction.
I would check this myself but from what you wrote above, I don't
understand for sure which years you intended.
On the Hebrew Calendar side, a friend of mine had loaned the Gandz
translation of "Kiddush haChodesh" to me several weeks ago. It has
English only, and was published after the death of the author, having
been completed by others. I found that I could not trust the
translation, presumably because those who finished the publication
didn't know what they were doing, or it could be the older English
style (early 1950s), so I have been studying the original Hebrew with
Rabbi Moshe Ginz. Yesterday I bought my own copy which has both
English and Hebrew and is a recent translation from the early 1990s, so
I am hoping that will be better. I want to implement computer
functions as per Maimonides' specifications and then compare the
agreement of his and mine for his era and ours. In several places he
uses approximations where none are necessary, or "quotas" instead of
interpolating, so I would also like to evaluate what difference it
makes not to do unnecessary approximations, and to interpolate between
the fixed quota values that he gives.
-- Irv Bromberg
Date: Mon, 3 Jan 2005 10:55:49 -0500
From: Rabbi Seed
Subject: Why the H in 5765H?
Remy,
Since I have the merit of announcing the new month this coming Shabbat,
just a few questions. I noticed on the announcement that on the year, you
have the letter 'g' after the English date and after the Hebrew date there
is an 'h'. Can you enlighten me?
Thanks
==============================
Rabbi David Seed
Adath Israel Congregation
37 Southbourne Avenue
Toronto, ON M3H 1A4
(416) 635-5340 x 321
Date: Mon, 3 Jan 2005 09:48:39 -0800 (PST)
---- Remy Landau replies
Dear Rabbi
The Hebrew year count is suffixed by 'H'
The Gregorian year count is suffixed by 'g'.
The Julian year count is suffixed by 'j'
This convention became necessary in working through the various
calendar arithmetic because each of these calendar systems uses
differently measured years in their calendar units.
For more on this rather confused calendar confusion, feel free to go to
Hebrew Calendar Science and Myths
and look into the CONVENTIONS.
The CE and BCE notations currently appearing in the various literatures
are futile since these do not distinguish between the Julian and the
Gregorian calendars... nor do these indicate whether or not the year
count also included a year zero between 1 BCE and 1 CE. and a few other
wrinkles in the matrix of the times....:)
Shannah Tovah;)
Remy Landau
Date: Tue, 4 Jan 2005 10:31:04 -0500
From: Rabbi Seed
Subject: Why Use the Julian Dates?
I checked out the website so now I understand the distinctions a bit
better.
By the way, where would there be any use for the Julian calendar or is
that just in calculating date prior to the use of the Gregorian calendar?
Thanks
==============================
Rabbi David Seed
Adath Israel Congregation
37 Southbourne Avenue
Toronto, ON M3H 1A4
(416) 635-5340 x 321
Date: Tue, 4 Jan 2005 07:49:12 -0800 (PST)
---- Remy Landau replies
Dear Rabbi
The Julian calendar is still very much in use world wide and most
notably in the Eastern Orthodox Church.
As an example, the EOC will be celebrating Christmas on January 7, 2005
which actually corresponds to December 25, 2004 in the Julian calendar.
The Tequfot are based on an arithmetic which assumes the solar year to
be 365.25 days long... the length of the solar year used by the Julian
calendar.
rl:)
Date: Wed, 12 Jan 2005 18:12:00 -0500
From: Irv Bromberg
Subject: Kalendis Molad Adjustment Calculation Update
To: "Remy Landau"
Date: Mon, 17 Jan 2005 09:57:47 EST
From: Dr. Bernard Dickman
Subject: The Molad and the First Day of the Month
Hi:
How are you? Once again I would appreciate your help.
I was discussing with my friend the relationship between the molad and
the first day of any month under our fixed calendar. I said that
the molad must occur on the first day of the month (even in rare occasions
after noon on the first) or the day before (which I said was the most
common situation) or the previous day ( two days before).
He asked what the frequency of each was and for some insight as to why
they happened. Also, he wanted to know if leap years were similar to
regular years in this respect. I replied that it was related to how close
the molad of Tishrei was to noon of Tishrei 1.
The biggest gaps between the molad of any month and the first of the month
would come in a year (and the preceding year) where we have a
Dehiyyah GaTaRad.
The smallest gaps would occur when the molad of Tishrei was immediately
preceding noon of Tishrei 1.
Was I correct?
Do you have any additional insights (such as frequency of occurence) into this issue?
Dr. Bernard Dickman
Date: Mon, 17 Jan 2005 08:26:01 -0800 (PST)
---- Remy Landau replies
Dear Bernard
Some of what you stated is in fact corroborated and some is at best
debatable.
Most of your questions seem to be answered in the web page under the
Moladot and the Overpost Problem...
Feel free to explore these areas of the web page.
Hodesh Tov!
Remy Landau
Date: Fri, 21 Jan 2005 16:11:11 -0500
From: Yosef Gavriel Bechhofer
Subject: Torah Science vs. Secular Chronology
I do not know who Mr. RMA is, but the charges below are
unsubstantiated.
The links he provides end in the webpage of a disaffected J's Witness,
where this information is not found. But a search led to another
disaffected J's Witness, whom RMA has plagarized:
http://watchtower.observer.org/apps/pbcs.dll/article?AID=/20040312/DOCTRINE2/122003
The citations, when viewed in the explanatory notes, are clearly seen
as interpreted to arrive at the result, and not as definitive.
(You may ask how this is relevant to disaffected JW's? It is because
the JW's claim the destruction was in 607, and this fellow, all of a tizzy,
tries to demonstrate that it is really 587.)
As to astronomy, au contraire, the Molados chart stretching to Molad
Tohu in perfect order debunks the claim. See:
http://www.geocities.com/Athens/1584/
(I am c'ing the masterful webmaster, Mr. Remy Landau.)
YGB
At 12:16 PM 1/21/2005, you wrote:
>I have followed the intricacies of the discussion on a multi billion
> year old universe vs. a 5765 year old one, but haven't seen any
> discussion on the details of what such a dating implies about more
> recent history.
>
> In particular Jewish and secular chronology are in synch only from 312
> BCE.
>
>The 275 year period preceding 312 BCE took only 110 years according to
>Sefer Olam Rabbah based chronology. For example according to Jewish
>Chronology the Bais Hamikdash was destroyed in 423 BCE and Alexander
>conquered Judea in about 320/319 BCE. How do we reconcile these dates?
>
>Was time moving at different rates for Am-Yisrael and the rest of the
>world at that time, so 27 hours in Sparta were the equivalent of 11
>hours in Jerusalem?
>
>Perhaps all of the non-Jewish records and data we have from antiquity
>which purport to tell us the names of ancient kings and their regnal
>periods are all forgeries or part of a grand conspiracy to confuse
>the Jews.
>
>In addition all the records of astronomical events we have are
> consistent with the 275 year chronolgy rather than the 110 year old one.
>
>Was physics operating differently before 312 BCE as well as during the
>creation period?
>
>In particular we have the following summary of archeological evidence
> for the secular neo-Babylonian chronology.
>
>(The evidence for dating Alexander's conquest of Judea to
>332 BCE is even more extensive.)
>
>* Chronicles, historical records, and royal inscriptions from the
> Neo-Babylonian period, beginning with the reign of Nabopolassar and
> ending with the reigns of Nabonidus and Belshazzar, show it ran from
> 626 to 539 BC.
>*
Date: Fri, 28 Jan 2005 00:58:02 -0500
From: Elizabeth Ranucci
Subject: Search for a Sunrise Alarm Clock
Well you are quite a bit smarter than I, but I did manage to scan a bit of your
lengthy and informative exegesis! I'm a Christian with a love for Israel, and
the Hebraic roots of our faith... my husband and I recently began enjoying
the Messianic Jewish community (not the ones who push Y'shua at the Jews -
rather the ones who desire to live a godly life, honor Torah, learn about
and practice the appointed Biblical feasts and celebrations ... with
Messianic significance ascribed to Y'shua - Jesus) and was just downloading
some great calendar conversion programs, etc. etc.
Actually, I was really looking for a clock which wakes you at sunrise so I can
get up then and pray. Not sure, but it seems the Jewish custom is to start
morning prayer at a certain interval before sunrise - but I never did find
that kind of clock, anyway!
Somehow I landed on your web page, (Google - gotta love it!) and will tab your
site as a Favorite, plus tell my husband about it.
Thanks! If you're interested, here's our church website: kehilat.org ...my
husbands written essays appear under Frank Ranucci in the "study" section.
He's got some good material in there, even if you're not Messianic -
about the Israeli-Palestinian conflict/myths, etc.
It's pro-Israel, of course :o)
Shalom!
Frank's wife
Date: Fri, 28 Jan 2005 02:25:20 -0800 (PST)
---- Remy Landau replies
Dear Elizabeth,
Thank you so much for the very encouraging words!
I'm not sure about any sunrise alarm clocks... let alone sunset
clocks... but I do know that there are considerable religious numbers
of religious opinions on these issues... not least of which revolve
around the issue of when it is that you can say that sunrise or sunset
has occured or is occurring. There are many answers to this particular
idea. As far as I know, the jury is still very much out on these issues
and the practices follow various customs set down by various
communities. Of course, the legal masters still have not quite come to
any concensus regarding sunrise and sunset in the Arctic regions,
although I have heard rumours of feeble attempts at this...
So good luck with your research into this topic!
Shabbat Shalom!
Remy Landau
Date: Tue, 1 Feb 2005 00:55:20 -0800
From: Yossi Yaffe
Subject: Searching for Date Conversion Formulas
Hi!
I was wondering if you could fill me in on the formula used to
calculate Hebrew to English date conversions.
Thanks!
Date: Tue, 1 Feb 2005 03:43:30 -0800 (PST)
---- Remy Landau replies
Dear Yossi,
There really aren't any well-known formulas to do this...
The closest you come to a well-known formula to convert from the Hebrew
to the Civilian date is the Gauss Pesach Formula... which, for good
reason, only provides the Julian equivalent of a Hebrew Pesach date...
but not the Gregorian. The Gauss effort, however, is only good for
about the first 9000 Hebrew years.
Most date conversion procedures today resort to a day count that
begins in some mythical past, like for example 1 Jan -4713j... and work
out the equivalences to that date using day counts from that starting
point.
This process is somewhat explained in such books as Reingold and
Dershowitz *Calendrical Calculations*...
But in general, it appears that everyone interested in calculating date
conversions will opt for their own formula to accomplish the obligatory
date conversions.
There are however some good internet sites devoted to the conversion of
calendar dates. Use Google to track down *Calendar Converter* for such
sites.
Best Regards
Remy Landau
Date: Sat, 05 Feb 2005 11:58:40 -0500
From: Paul Moniodis
Subject: Request for Historical List of Passover Dates
Do you know of a reference that gives a list of the Passover dates from
ca. 1 CE till present? Many hours of internet searching proved
unsucessful. Thank you.
Paul Moniodis
Date: Sat, 5 Feb 2005 17:22:10 -0800 (PST)
---- Remy Landau replies
Dear Paul,
Attached is a list specially created in response to your request.
The list shows the Hebrew year, followed by the Gregorian date, and
then the Julian date.
You must be aware of the fact that this list consists of a formal
calculation and cannot pretend to be historical fact much beyond the
year 900 CE since the fixed Hebrew calendar does not appear to have
emerged in its present form until about that period in time.
Shavuah Tov!
Hodesh Tov!
Remy Landau
Plain Text Attachment (edited by Remy Landau)
About the turn of the 1st century CE
Pesach 3,750H maps onto Tue 27 Mar -10g ( 29 Mar -11j)
Pesach 3,751H maps onto Tue 16 Apr -9g ( 18 Apr -10j)
Pesach 3,752H maps onto Sat 4 Apr -8g ( 6 Apr -9j)
Pesach 3,753H maps onto Thu 25 Mar -7g ( 27 Mar -8j)
Pesach 3,754H maps onto Tue 12 Apr -6g ( 14 Apr -7j)
Pesach 3,755H maps onto Sat 1 Apr -5g ( 3 Apr -6j)
Pesach 3,756H maps onto Thu 21 Mar -4g ( 23 Mar -5j)
Pesach 3,757H maps onto Thu 10 Apr -3g ( 12 Apr -4j)
Pesach 3,758H maps onto Sun 29 Mar -2g ( 31 Mar -3j)
Pesach 3,759H maps onto Thu 18 Mar -1g ( 20 Mar -2j)
Pesach 3,760H maps onto Thu 6 Apr 0g ( 8 Apr -1j)
Pesach 3,761H maps onto Tue 27 Mar 1g ( 29 Mar 1j)
Pesach 3,762H maps onto Sun 14 Apr 2g ( 16 Apr 2j)
Pesach 3,763H maps onto Thu 3 Apr 3g ( 5 Apr 3j)
Pesach 3,764H maps onto Tue 23 Mar 4g ( 25 Mar 4j)
Pesach 3,765H maps onto Tue 12 Apr 5g ( 14 Apr 5j)
Pesach 3,766H maps onto Sat 1 Apr 6g ( 3 Apr 6j)
Pesach 3,767H maps onto Tue 20 Mar 7g ( 22 Mar 7j)
Pesach 3,768H maps onto Tue 8 Apr 8g ( 10 Apr 8j)
Pesach 3,769H maps onto Sat 28 Mar 9g ( 30 Mar 9j)
Pesach 3,770H maps onto Thu 15 Apr 10g ( 17 Apr 10j)
...
Possible years of the crucifixion
Pesach 3,789H maps onto Sun 15 Apr 29g ( 17 Apr 29j)
Pesach 3,790H maps onto Thu 4 Apr 30g ( 6 Apr 30j)
Pesach 3,791H maps onto Tue 25 Mar 31g ( 27 Mar 31j)
Pesach 3,792H maps onto Tue 13 Apr 32g ( 15 Apr 32j)
Pesach 3,793H maps onto Sat 2 Apr 33g ( 4 Apr 33j)
Pesach 3,794H maps onto Tue 21 Mar 34g ( 23 Mar 34j)
Pesach 3,795H maps onto Tue 10 Apr 35g ( 12 Apr 35j)
Pesach 3,796H maps onto Sat 29 Mar 36g ( 31 Mar 36j)
Pesach 3,797H maps onto Thu 19 Mar 37g ( 21 Mar 37j)
Pesach 3,798H maps onto Tue 6 Apr 38g ( 8 Apr 38j)
Pesach 3,799H maps onto Sat 26 Mar 39g ( 28 Mar 39j)
Pesach 3,800H maps onto Sat 14 Apr 40g ( 16 Apr 40j)
...
Period of the destruction of the second Bet HaMiqdash
Pesach 3,826H maps onto Sat 27 Mar 66g ( 29 Mar 66j)
Pesach 3,827H maps onto Sat 16 Apr 67g ( 18 Apr 67j)
Pesach 3,828H maps onto Tue 3 Apr 68g ( 5 Apr 68j)
Pesach 3,829H maps onto Sun 24 Mar 69g ( 26 Mar 69j)
Pesach 3,830H maps onto Sat 12 Apr 70g ( 14 Apr 70j)
Pesach 3,831H maps onto Thu 2 Apr 71g ( 4 Apr 71j)
Pesach 3,832H maps onto Sun 20 Mar 72g ( 22 Mar 72j)
Pesach 3,833H maps onto Sat 8 Apr 73g ( 10 Apr 73j)
...
Period possibly at about the time of the Gamliel-Yehoshuah mahloqet
Pesach 3,855H maps onto Thu 7 Apr 95g ( 9 Apr 95j)
Pesach 3,856H maps onto Sun 25 Mar 96g ( 27 Mar 96j)
Pesach 3,857H maps onto Sat 13 Apr 97g ( 15 Apr 97j)
Pesach 3,858H maps onto Thu 3 Apr 98g ( 5 Apr 98j)
Pesach 3,859H maps onto Tue 24 Mar 99g ( 26 Mar 99j)
Pesach 3,860H maps onto Sun 11 Apr 100g ( 12 Apr 100j)
...
Period at about the time of the ill-fated Bar Kochba revolt
Pesach 3,890H maps onto Tue 11 Apr 130g ( 12 Apr 130j)
Pesach 3,891H maps onto Sat 31 Mar 131g ( 1 Apr 131j)
Pesach 3,892H maps onto Tue 18 Mar 132g ( 19 Mar 132j)
Pesach 3,893H maps onto Tue 7 Apr 133g ( 8 Apr 133j)
Pesach 3,894H maps onto Sat 27 Mar 134g ( 28 Mar 134j)
Pesach 3,895H maps onto Thu 14 Apr 135g ( 15 Apr 135j)
Pesach 3,896H maps onto Tue 3 Apr 136g ( 4 Apr 136j)
Pesach 3,897H maps onto Sat 23 Mar 137g ( 24 Mar 137j)
Pesach 3,898H maps onto Sat 12 Apr 138g ( 13 Apr 138j)
Pesach 3,899H maps onto Tue 31 Mar 139g ( 1 Apr 139j)
Pesach 3,900H maps onto Sun 20 Mar 140g ( 21 Mar 140j)
...
Period at about the time of Hillel II's supposed calendar reform
Pesach 4,114H maps onto Sat 27 Mar 354g ( 26 Mar 354j)
Pesach 4,115H maps onto Thu 14 Apr 355g ( 13 Apr 355j)
Pesach 4,116H maps onto Tue 3 Apr 356g ( 2 Apr 356j)
Pesach 4,117H maps onto Sat 23 Mar 357g ( 22 Mar 357j)
Pesach 4,118H maps onto Sat 12 Apr 358g ( 11 Apr 358j)
Pesach 4,119H maps onto Tue 31 Mar 359g ( 30 Mar 359j)
Pesach 4,120H maps onto Sat 19 Mar 360g ( 18 Mar 360j)
Pesach 4,121H maps onto Sat 8 Apr 361g ( 7 Apr 361j)
Pesach 4,122H maps onto Thu 29 Mar 362g ( 28 Mar 362j)
Pesach 4,123H maps onto Tue 16 Apr 363g ( 15 Apr 363j)
Pesach 4,124H maps onto Sat 4 Apr 364g ( 3 Apr 364j)
Pesach 4,125H maps onto Thu 25 Mar 365g ( 24 Mar 365j)
...
Period at about the time of the Resh Galuta's letter of 4,595H
Pesach 4,590H maps onto Tue 16 Apr 830g ( 12 Apr 830j)
Pesach 4,591H maps onto Sat 5 Apr 831g ( 1 Apr 831j)
Pesach 4,592H maps onto Thu 25 Mar 832g ( 21 Mar 832j)
Pesach 4,593H maps onto Tue 12 Apr 833g ( 8 Apr 833j)
Pesach 4,594H maps onto Sat 1 Apr 834g ( 28 Mar 834j)
Pesach 4,595H maps onto Thu 22 Mar 835g ( 18 Mar 835j)
Pesach 4,596H maps onto Thu 10 Apr 836g ( 6 Apr 836j)
Pesach 4,597H maps onto Sun 29 Mar 837g ( 25 Mar 837j)
Pesach 4,598H maps onto Sat 17 Apr 838g ( 13 Apr 838j)
...
Period at about the time of the Meir-Saadia mahloqet
Pesach 4,678H maps onto Tue 5 Apr 918g ( 31 Mar 918j)
Pesach 4,679H maps onto Sat 25 Mar 919g ( 20 Mar 919j)
Pesach 4,680H maps onto Thu 11 Apr 920g ( 6 Apr 920j)
Pesach 4,681H maps onto Tue 1 Apr 921g ( 27 Mar 921j)
Pesach 4,682H maps onto Tue 21 Apr 922g ( 16 Apr 922j)
Pesach 4,683H maps onto Sat 10 Apr 923g ( 5 Apr 923j)
Pesach 4,684H maps onto Tue 28 Mar 924g ( 23 Mar 924j)
Pesach 4,685H maps onto Tue 17 Apr 925g ( 12 Apr 925j)
Pesach 4,686H maps onto Sat 6 Apr 926g ( 1 Apr 926j)
Pesach 4,687H maps onto Thu 27 Mar 927g ( 22 Mar 927j)
Pesach 4,688H maps onto Tue 13 Apr 928g ( 8 Apr 928j)
...
Period at about the time of Maimonides' Hilkhot Qiddush HaHodesh
Pesach 4,930H maps onto Thu 9 Apr 1,170g ( 2 Apr 1,170j)
Pesach 4,931H maps onto Tue 30 Mar 1,171g ( 23 Mar 1,171j)
Pesach 4,932H maps onto Tue 18 Apr 1,172g ( 11 Apr 1,172j)
Pesach 4,933H maps onto Sat 7 Apr 1,173g ( 31 Mar 1,173j)
Pesach 4,934H maps onto Tue 26 Mar 1,174g ( 19 Mar 1,174j)
Pesach 4,935H maps onto Tue 15 Apr 1,175g ( 8 Apr 1,175j)
Pesach 4,936H maps onto Sat 3 Apr 1,176g ( 27 Mar 1,176j)
Pesach 4,937H maps onto Thu 24 Mar 1,177g ( 17 Mar 1,177j)
Pesach 4,938H maps onto Tue 11 Apr 1,178g ( 4 Apr 1,178j)
Pesach 4,939H maps onto Sat 31 Mar 1,179g ( 24 Mar 1,179j)
Pesach 4,940H maps onto Sat 19 Apr 1,180g ( 12 Apr 1,180j)
...
Period at about the time of the Gregorian calendar reform
Pesach 5,338H maps onto Sun 2 Apr 1,578g ( 23 Mar 1,578j)
Pesach 5,339H maps onto Sat 21 Apr 1,579g ( 11 Apr 1,579j)
Pesach 5,340H maps onto Thu 10 Apr 1,580g ( 31 Mar 1,580j)
Pesach 5,341H maps onto Sun 29 Mar 1,581g ( 19 Mar 1,581j)
Pesach 5,342H maps onto Sat 17 Apr 1,582g ( 7 Apr 1,582j)
Pesach 5,343H maps onto Thu 7 Apr 1,583g ( 28 Mar 1,583j)
Pesach 5,344H maps onto Tue 27 Mar 1,584g ( 17 Mar 1,584j)
Pesach 5,345H maps onto Sun 14 Apr 1,585g ( 4 Apr 1,585j)
Pesach 5,346H maps onto Thu 3 Apr 1,586g ( 24 Mar 1,586j)
Pesach 5,347H maps onto Thu 23 Apr 1,587g ( 13 Apr 1,587j)
Pesach 5,348H maps onto Tue 12 Apr 1,588g ( 2 Apr 1,588j)
Pesach 5,349H maps onto Sat 1 Apr 1,589g ( 22 Mar 1,589j)
Pesach 5,350H maps onto Thu 19 Apr 1,590g ( 9 Apr 1,590j)
...
Current period
Pesach 5,757H maps onto Tue 22 Apr 1,997g ( 9 Apr 1,997j)
Pesach 5,758H maps onto Sat 11 Apr 1,998g ( 29 Mar 1,998j)
Pesach 5,759H maps onto Thu 1 Apr 1,999g ( 19 Mar 1,999j)
Pesach 5,760H maps onto Thu 20 Apr 2,000g ( 7 Apr 2,000j)
Pesach 5,761H maps onto Sun 8 Apr 2,001g ( 26 Mar 2,001j)
Pesach 5,762H maps onto Thu 28 Mar 2,002g ( 15 Mar 2,002j)
Pesach 5,763H maps onto Thu 17 Apr 2,003g ( 4 Apr 2,003j)
Pesach 5,764H maps onto Tue 6 Apr 2,004g ( 24 Mar 2,004j)
Pesach 5,765H maps onto Sun 24 Apr 2,005g ( 11 Apr 2,005j)
Pesach 5,766H maps onto Thu 13 Apr 2,006g ( 31 Mar 2,006j)
Pesach 5,767H maps onto Tue 3 Apr 2,007g ( 21 Mar 2,007j)
Pesach 5,768H maps onto Sun 20 Apr 2,008g ( 7 Apr 2,008j)
Pesach 5,769H maps onto Thu 9 Apr 2,009g ( 27 Mar 2,009j)
Pesach 5,770H maps onto Tue 30 Mar 2,010g ( 17 Mar 2,010j)
Date: Sun, 6 Feb 2005 17:51:04 EST
From: Paul Moniodis
Thank you for your kind and generous labor. Much appreciated.
Paul Moniodis
Date: Thu, 10 Feb 2005 14:54:57 -0500
From: Giora Magen
Subject: Request for Hebrew Year Number Transliteration
Dear Remy/Landau
Do you have a chart or converter to transform the Hebrew year,
into Hebrew letters? for example, 5739 into tav shin lamed '' tet
Thank you
Giora Magens
Date: Thu, 10 Feb 2005 13:03:55 -0800 (PST)
---- Remy Landau replies
Dear Giora
That is an interesting idea which, to the best of my knowledge, has not
been developed.
Perhaps someone else will know of a source to satisfy this request.
Hodesh Tov!
Remy Landau
Date: Wed, 16 Feb 2005 14:16:03 +0000
From: Dr. John Stockton
Subject: Is Creation at AM 1 or AM 2?
Claus Tondering's The Calendar FAQ, V2.7 (2005-01-15), has a Section
3.8 changed from that of V2.6 (2003).
URL: http://www.tondering.dk/claus/calendar.html
V2.6 :
Years are counted since the creation of the world, which is assumed to
have taken place in 3761 BC. In that year, AM 1 started (AM = Anno
Mundi = year of the world).
V2.7 :
Years are counted since the creation of the world, which is assumed to
have taken place in the autumn of 3760 BC. In that year, after less
than a week belonging to AM 1, AM 2 started (AM = Anno Mundi = year of
the world).
Written references at home here agree with V2.6.
If you can confirm V2.7, I'll need to change my web pages; do you have
a Julian calendar date/time for the Creation and for the start of AM 2 ?
If you can refute V2.7, you might like to tell Claus Tondering -
'E-mail: claus@tondering.dk. (Please include the word "calendar" in the
subject line.)'.
Otherwise, ???
One must note that only half of the world can have been created
in the Autumn, the other half must have been created in Spring.
Regards,
John Stockton, Surrey, UK.
Date: Wed, 16 Feb 2005 17:21:29 -0800 (PST)
---- Remy Landau replies
Dear John
The mythical legends of the rabbis suggest that something existed as of
Year 1H... but that Bereshit (ie Creation) began in the very last six
days of that first year.
Thus Adam was created on the last Friday of that year and on Shabbat
Year 2H began.
The tradition is found in many medieval sources.
If the year count begins with year 1H with Tishrei molad of BaHaRaD (ie
2d 5h 204p) then the years which follow (currently year 5765H, are
collectively known as the years of Anno Mundi (or AM).
If the year count begins with year 2H and molad of Tishrei of VaYaD (ie
6d 14h 0p) then the years which follow, currently at 5764, are
collectively known as the years of Aera Adami (or AA).
There is also the year of contracts, which is a year count begun with
the ascension of Alexander the Great in -312j.
All of these year counts are documented in medieval writings, and may
be found in Maimonides' *Hilkhot Qiddush HaHodesh* (1175j), and also
Al-Biruni's *Chronology of the Ancient Nations* (1000j).
A good web site for converting specific dates over a very large time
span is found at
Calendar Converter
From the above it appears that no change need be made to any of the
documentation you have noted.
Shabbat Shalom!
Remy Landau
Date: Thu, 17 Feb 2005 10:59:26 +0200
From: Eli Nahmani
Subject: What is the Real Purpose of the Dehiyyot?
Dear Remy,
First of all I would like to express my appreciation to your excellent web site,
both from informational and design points of view.
In the paragraph "The 4 Dehiyyot" you say that the purpose of the Dehiyyot is
to reduce the number of Qeviyyot.
What is the interest of the Hebrew calendar to reduce that number?
Are you saying that the motivation of "Lo ADU Rosh" is not really
to prevent Yom Kippur from occurring near Shabbat?
Thanks for your patience..
Regards,
Eli Nahmani
Tel-Aviv, Israel
Date: Thu, 17 Feb 2005 03:11:51 -0800 (PST)
---- Remy Landau replies
Dear Eli
That is quite correct... in spite of some rabbinic and Talmudic
comments on this issue..
Deeper probing has shown that the Dehiyyot were instituted purely for
arithmetical purposes and as well to pay very close heed to the Mishnah
found in Tractate Arakin 8b.
Shabbat Shalom
Remy Landau
----
Date: Thu, 17 Feb 2005 14:22:39 +0200
From: Eli Nahmani
Dear Remy,
Thank you very much for your fast response.
But still, what is "wrong" with too many Qeviyyot ?
(Is this answered in the Mishnaa you have mentioned?)
Thanks,
Shabbat Shalom
Eli
Date: Thu, 17 Feb 2005 06:31:04 -0800 (PST)
---- Remy Landau replies
Dear Eli,
A qeviyyah specifies the structure of the year.
Without the dehiyyot there would be 28 such structures.
With the dehiyyot there are 14 qeviyyot.
This considerably reduces the effort in documenting the manner in which
such religious practices as the Torah reading ought to be split during
the year... and many other matters which depend on the structure of the
year.
With regards to the issue of too many qeviyyot, you would then come
squarely against the matter stated in Arakin 8b, And therefore
overriding the Talmud.
One day, this will be explained in the page.
Shabbat Shalom!
Remy Landau
----
Date: Sun, 20 Feb 2005 17:02:33 +0200
From: Eli Nahmani
Dear Remy,
Thank you very much again for your quick reply and your patience.
I will be very glad to read your explanation about the influence of the
dehiyyot on religious routines.
Can you please give me just one or 2 examples of additional
instructions/documentation regarding religious practices that would be necessary if "Lo ADU" was not implemented (sorry for my English).
Regards,
Shavuah Tov.
Eli Nahmani
Date: Sun, 20 Feb 2005 09:19:54 -0800 (PST)
---- Remy Landau replies
Dear Eli,
The web page, in discussing the dehiyyot, notes the effects of not
having the rule Lo ADU.
Feel free to work out the religious details.
Shavuah Tov!
Remy Landau
Date: Tue, 1 Mar 2005 09:09:34 -0800 (PST)
From: Gregory David
Subject: Why Are There So Many Hebrew Year Lengths?
Dear Sir :
I am a Christian and as such believe the bible to be the very word of GOD.
It is, among other things, an accurate (infallable ) history of the world.
I visited your site to better understand the basics of the Hebrew year and
thus the time of year that Christ was born and the time of year that he died.
I am sorry to say though that I found your site to be vague and convoluted
(to my western mind).
Why, for example, are there so many different lengths to the years ?
Since the earth circles the sun with clockwork accuracy, the calculation of that
year should be precise and not spread into a comlicated sytem of periods. The
pentatuch gives no indication that God meant for such a complicated system to arise.
So where does it come from and when was it established ?
Any clarification on this would be greatly appreciated.
SGT. David, Gregory C.
U.S. Army
Date: Tue, 1 Mar 2005 10:29:04 -0800 (PST)
---- Remy Landau replies
Dear Gregory,
The biblical text to which you refer presented the very basic
fundamentals of the calendar year.
This was a year that had to respond to the Roshei Hadashim, that is, the
New Moons, and as well, to the seasons that are byproducts of the years
as measured by the anuual solar cycle.
The result was a luni-solar calendar.
Of particular importance was the recognition that complete cycles of
the moon did not particularly match up with complete cycles of the sun.
Thus, the luni-solar calendar system of the Hebrews was established in
such a manner so as to prevent the onset of any Lunar year from
drifting more than 30 days from the onset of its corresponding solar
year in the luni-solar system cycle.
Possibly the ancient Babylonians, or at the very least, the ancient
Greek astronomer Meton, found that 235 lunar months very closely
approximated the time needed to complete 19 annual solar cycles.
Thus was born the Meton cycle in which 12-month years are followed by
13-month years in such a manner that no lunar year begins more than one month
from the start of its corresponding solar year in that cycle.
With regards to years having different lengths, a complete explanation
is given in the Additional Notes under the topic of Properties of Hebrew Year Periods.
Thank you for your remarks.
Remy Landau
----
Date: Wed, 2 Mar 2005 09:13:08 -0800 (PST)
From: Gregory David
Subject: Why Are There So Many Hebrew Year Lengths?
Dear Mr. Landau :
Thank you very much for taking the time to answer my letter.
Your explanation was precise and lucid. Now I think I have a foundation from
which to begin my study.
I wonder what we can discern about God, His earth, and human history (if anything )
from such a study. I do not believe the Almighty is superfluous or capricious
in the least. It is my conviction that everthing in God's economy has a place
and purpose in the excecution of His plan...down to the jot and title.
Should you have anything else to teach me on this topic I would be fascinated to
delve deeper. For Example, doesn't God tell the Israelites in Exodus that the
Passover is the beginning of their year ? What time of the year is that?
Christ was betrayed, condemned and crucified during the Passover. Does it
correspond to the catholic celebration of easter ? What is the relationship
between the Roshei Hadashim and Passover ?
A Very Curious
Sgt. David, Gregory C.
U.S. Army
Date: Wed, 2 Mar 2005 12:09:28 -0800 (PST)
---- Remy Landau replies
Dear Gregory
Since the information contained in the web page is about the
calculation of the Hebrew calendar, and not about theology, your
questions here will have to be answered through other resources.
Regarding the Roshei Hadashim, these are the heads of the months,
literally.
Biblically, Exodus 12:2 implies that the Exodus took place in the
middle of a particular month to be regarded as the first of "your
months".
A number of rabbinic traditions, in the absence of any tangible
historical record, have suggested this "first month" to be the month of
Nisan, and of course the Pesach to have been observed on the 15th day
of that month.
That is about as far as the matter can be taken in the absence of any
particular archeological, historical, or other tangibly real record.
Best Regards,
Remy Landau
Date: Mon, 7 Mar 2005 14:26:51 -0500
From: Irv Bromberg
Subject: Maimonides and the Length of the Seasons
I have been studying Maimonides "Hilkhot Qiddush HaHodesh" with Rabbi Moshe
Ginz.
After we learned about Rambam's method for calculating the moment
of the equinoxes and solstices, which is based on the assumption that
the season lengths are fixed and equal in length, I decided to take an
astronomical algorithm look at the matter, and found that at most only
two seasons can be equal in length (and that only happens when
perihelion is at an equinox or solstice or the mid-season point), the
seasons can vary in length by up to 7 days, and that the variability
decreases as the Earth orbital eccentricity decreases.
Please check out my new web page entitled "The Lengths of the Seasons".
http://individual.utoronto.ca/kalendis/
Regards, Dr. Irv Bromberg, University of Toronto, Canada
Date: Thu, 10 Mar 2005 17:30:48 -0500
From: Robert E. Heyman
Subject: Shabbats of Three Torahs
Remy,
The following came from ou.org. I thought you might appreciate it, if
you haven't seen it.
Robert
With this coming Shabbat being Sh'kalim and Rosh Chodesh, in addition
to Parshat P'kudei, we will be reading from three Torahs. Here, then, is
almost everything you ever wanted to know about 3-Torah Shabbatot
[3TSh], and probably more.
Simchat Torah is always a 3-Torah day, but it isn't always on Shabbat,
In Chutz LaAretz, it NEVER is. In Eretz Yisrael, Simchat Torah falls on
Shabbat 28½% of the time (when- ever Rosh HaShana is Shabbat).
The next possible 3TSh is Shabbat Chanuka, when Rosh Chodesh Tevet is
Shabbat. (Specifically, it is 30 Kislev - first day of Rosh Chodesh
Tevet - that can be Shabbat; the first of Tevet does not fall on Shabbat.)
This happens 28% of the time - never in the same year as Simchat Torah on
Shabbat.
The final two candidates for 3TSh are Sh'kalim and HaChodesh when their
Rosh Chodesh (Adar or Adar Sheni for Sh'kalim and Nissan for HaChodesh)
falls on Shabbat. HaChodesh is a 3TSh 28% of the years, and Sh'kalim,
only 11½% of the time (including this year). 3TSh for Sh'kalim happens in
the same year-types as Triple Purim and Erev Pesach on Shabbat.
In Chutz LaAretz, 42½% of years have no 3TSh, and 10% have two (Chanuka
and HaChodesh).
Years with 3TSh are slightly more common than ones without.
In Eretz Yisrael, 3TSh are very common. Only 18% of years have no 3TSh.
Over 14% have two. (In addition to Chanuka and HaChodesh, there is also
one year-type with Simchat Torah and Sh'kalim.)
Date: Mon, 14 Mar 2005 08:54:42 -0800 (PST)
From: William Jacobson
Subject: Request for Remy Landau's Qualifications
Mr. Landau,
I am studying your documents relating to the Jewish
calendar with fascination. There is obviously an
awful lot to understand. Before I commit myself to
plowing through all this material, I wonder if I might
respectfully inquire as to your bona fides to write on
this subject.
Can you please share with me your educational
background?
thanking you in advance,
bill jacobson
Date: Mon, 14 Mar 2005 10:25:10 -0800 (PST)
---- Remy Landau replies
Dear William,
Welcome to the web page. I hope that you will enjoy its content,
and perhaps find answers to your questions on the Hebrew calendar.
It is always a pleasure to communicate with readers of the page, and I
certainly look forward to continued correspondence from you.
Shavuah Tov!
Remy Landau
Date: Mon, 14 Mar 2005 13:53:23 -0700
From: Donald Pullen
Subject: What is the Correct Day for Shabbat?
Hello,
I am doing research on the Shabbat.
I found your website and I am in hopes that you could help me with a question.
Using the most ancient record of the Hebrew Calendar, by what method did the
earliest Hebrews determine which actual day was the correct day for Shabbat?
I have conjectured that it centered around moon phases and therefore 2 days
before any of the four major phases was determined as the Shabbat.
ie.. Monday being a moonday and Shabbat being Saturday.
If you could please give me insight on this question and if you have any
references to this, I would deeply appreciate it.
Thanks,
Don Pullen
Date: Mon, 14 Mar 2005 17:56:28 -0800 (PST)
---- Remy Landau replies
Dear Donald,
Since this question is well beyond the limits of my knowledge, I will
have to demur.
Respectfully,
Remy Landau
Date: Wed, 23 Mar 2005 09:35:09 +0200
From: Eli Nahmani
Subject: Hebrew Calendar PC Calculation Accuracies
Hi dear Remy,
The article "Calendars" by L. E. Doggett states that "To avoid rounding
and truncation errors, calculation should be done in halakim rather than decimals
of a day...", which is certainly correct.
But I wondered how wrong a "floating point" calculation can be.
I have checked the two methods over 700,000 years and I have discovered
that when there is a difference between "floating-point" calculation
(using double precision on a PC platform) and "integer" calculation, then
the FP result is always less than the INT result by 1 Heleq.
Nevertheless, differences are never around day transition (i.e.
23h,1079p instead of 0h,0p) or around 18h (i.e. 17h,1079p instead of 18h,0p).
So, the molad Tishrei and the first 2 Dehiyyot are always correct. And
if you implement the last 2 dehiyyot by calculating the number of days
of the "previous" and "next" year and check them for 382/356 then
you get the right result using FP calculation.
What do you think ?
Regards,
Purim Sameach,
Eli Nahmani
Date: Wed, 23 Mar 2005 02:10:27 -0800 (PST)
---- Remy Landau replies
Dear Eli,
The calculation errors derived are highly dependent on the floating
point arithmetic methods implemented in your computer... for example,
the IEEE standard appears to provide greater accuracy than the
alternative but faster method that some operating systems allow.
With regards to double precision arithmetic, at least in the PC
environments of today, the maximum positive dp integer appears to be
2^32 - 1, while the maximum dp float point number is about 15 digits
accurate, since the fp dp uses 64 bits, of which either 8 or 12 are
reserved for the exponent.
Now, getting back to the calendar calculations, I'm not aware from your
correspondence how far into the calculations you appear to be going to
get the one heleq difference between floating point and integer
arithmetic. But from your letter, it doesn't seem to be too far.
Now, if you stick to calculating in halaqim rather than in decimals of
a day, as suggested by L. E. Dogget, and you use the floating point
arithmetic available to most PC's, then you'll find that you can
correctly calculate the moladot up to at least the Hebrew year
24,660,582,124,551H.
That upper limit is very nice to have since it is monumentally well
beyond the Hebrew-Gregorian calendar cycle of
14,389,970,112 Hebrew years which is also 14,390,140,400 Gregorian years.
It is interesting to note that you appear to have overcome a calculation problem
by implementing the 356/382 bypass shown by Reingold and Dershowitz
in their formidable work Calendrical Calculations. The
technique was the subject of Weekly Questions 148 and 149
which may be found in the Weekly Question Archive.
My preference, nevertheless, is to continue to use the classical timings
of GaTaRaD and B'TUK'TaPoT. These two Dehiyyot are much easier to implement in computer
algorithms that are used to determine the various lengths of Hebrew year periods.
The differing lengths of Hebrew year periods are considered
in Properties of Hebrew Year Periods.
Thank you for sharing with me the results of your very interesting
researches into one of the more intriguing aspects of using computers
on the arithmetic of the Hebrew calendar.
Shalom!
Remy Landau
Date: Tue, 29 Mar 2005 16:54:37 -0500
From: Irv Bromberg
Subject: Request for Rain Web Site
Today I posted my new web page about Request for Rain (Sh'ela), and
would appreciate your comments.
(You may find the "fine print" comments about Maimonides' calculations
especially interesting.)
http://individual.utoronto.ca/kalendis/shela.htm
Regards, Irv Bromberg.
Date: Fri, 1 Apr 2005 10:48:03 -0800 (PST)
From: Shlomo Abrahams
Subject: Hebrew Calendar Science and Myths
I really enjoyed your website about the Hebrew calendar..
Thanks
Date: Sat, 2 Apr 2005 17:37:45 -0800 (PST)
---- Remy Landau replies
Dear Shlomo
Thank you so much for the very encouraging words!
Shavuah Tov!
Remy Landau
Shlomo Abrahams
Date: Sun, 03 Apr 2005 20:43:59 +0100
From: Rachel Brown
Subject: The Molad Drift
Mr Landau
As a friend of the Jewish people, I am very interested in the Jewish
calendar and found your web site invaluable. I have struggled through
Maimonides' exposition, but you have made it far clearer and added many
great insights.
I do, however, have a query on your article about the Molad Drift. You
quote the mean length of the lunar month, and imply that it is
constant.
However, this is not true. Compared with a day of fixed length, the
month is getting longer. Also, the day itself is getting longer as
measured by atomic clocks, so compared with these variable days the
month is actually getting shorter. I am happy to supply some references
if you want to follow this up.
The length of the year is also changing; I can't remember offhand
whether it is getting longer or shorter compared with a day of
fixed length, though I think the change is much slower than for months.
May I wish you chazak and Shabbat Shalom, and may you indeed live to
the longest possible 120 to continue your work.
Rachel Brown
Date: Sun, 3 Apr 2005 15:57:19 -0700 (PDT)
---- Remy Landau replies
Dear Rachel,
Thank you so much for your encouraging words...
Perhaps one day the topic will be expanded to include the rather
excellent observation that you have made.
But at the present time, more calendar material is being researched and
accumulated, precluding the attention needed for this detail.
Shavuah Tov!
Remy Landau
Date: Tue, 5 Apr 2005 07:44:59 -0600
From: John Dekkers
Subject: When is Shmittah?
Dear Sir:
I found your site as I was hunting for a Jewish calendar to tell me when
the next Year of Release or Shabbat Year starts. It is the year in which
debts to our brothers are to be cancelled. As a businessman and believer, I
want to start to honor that instruction of our Lord. But the church has
wholly (and conveniently?) forgotten it...
Hope you can help.
With warm regards,
John
Date: Tue, 5 Apr 2005 16:16:45 -0700 (PDT)
---- Remy Landau replies
Dear John,
That will be the year 5768H, beginning on Thu 13 Sep 2007g.
The year of shmittah is, by one of these amazing coincidences, always
supposed to be a multiple of 7.
Best Regards
Remy Landau
Date: Thu, 7 Apr 2005 08:51:08 -0600
From: Hans Dekkers
Dear Remy:
Many thanks for your reply! Very much appreciated! We will add
observance to this instruction to our lives.
G-d is good! And his Law is perfect!
And His grace... limitless!
Warm regards,
Hans
Date: Wed, 06 Apr 2005 23:41:52 -0500
From: Amy Lui
Subject: Top Spiritual Site Award 2005
Hello!
This is Amy, Junior Editor for spiritandsky.com, the internet's
authority hub for spiritual related web sites.
Welcome, and congratulations on such a wonderful site =).
As part of my new job here at Spirit and Sky, I spend my time visiting
sites and giving awards to those that deserve it.
So congratulations for having a VERY relevant, on-topic site, and thank
you for making the internet a better place! :)
With hopes of love, light, music and happiness, thank you for your
time!
Amy Lui
Spirit and Sky! Junior Editor
http://www.spiritandsky.com
Date: Thu, 7 Apr 2005 02:32:41 -0700 (PDT)
---- Remy Landau replies
Dear Amy,
Thank you very much for your very encouraging words.
And your very meaningful recognition of the efforts that made possible
the contents of this site.
Hodesh Tov!
Remy Landau
Date: Sun, 10 Apr 2005 08:57:20 -0400
From: Jack Gostl
Subject: Why One and Two Days Rosh Hodesh?
Hello
I am trying to understand why a month with 29 days is followed by a one day
Rosh Hodesh but a month with 30 days is followed by two days of
Rosh Hodesh.
This seems counter intuitive. I suspect there is a mathematical reason simply
because there is nothing arbitrary about the Hebrew calendar.
(At least nothing I have turned up.)
Thanks
Jack
Date: Sun, 10 Apr 2005 06:25:17 -0700 (PDT)
---- Remy Landau replies
Dear Jack,
The unofficial take on this issue is that there was a desire to
maintain unbroken the cycle of weekdays over the Roshei Hadashim.
When a month has 29 days, then the start of the next month will be on
the week day immediately following the start of the previous month.
That's because 29 days is 4 whole weeks plus 1 day.
When a month has 30 days, then the start of the next month will be on
the week day two days removed from the start of the previous month.
That's because 30 days is 4 whole weeks plus 2 days.
Consequently, there is an obvious break in the weekdays between the 1st
days of these two months. To fill that gap, Rosh Hodesh is also
declared on the 30th day of the month.
In this way the Roshei Hadashim always maintain a completely unbroken
weekday cycle.
There are several additional observations which can be made with
regards to this arrangement of the Roshei Hadashim.
At the technical level, this provides a very important error detection
mechanism for the Hebrew calendar maker. Namely, the 30th day of each
month must always be on the weekday immediately following the the first
day of the previous month. Thus, the calculations leading to the first
day of Tishrei have a very powerful verification mechanism.
Also, it may be noted that Rosh Hodesh will always be on the
30th day of each and every single month. This has implications in
terms of the annual memorial date (yahrzeit), and is used
by many communities to deal with a date of bereavement that is the
30th day of either the months of Heshvan, Kislev, and Adar HaRishon.
Hodesh Tov!
Shavuah Tov!
Remy Landau
Date: Mon, 18 Apr 2005 01:31:22 -0400
From: Ari Meir Brodsky
Subject: Yaaqov Loewinger's Recent Article on 5765
Dear Dr. Bromberg and Remy Landau,
I think you will be interested in the attached article, although I
don'tknow whether your Hebrew is good enough to read it. It is written by
Yaaqov Loewinger, who is a civil engineer by profession, but also a big talmid
chakham and a calendar expert.
The title translates as "Have we intercalated the year 5765 in vain?"
(my translation).
In the article, he presents the background to the problem, which of course
you already know, and explains that there are scholars who have suggested
that the Jewish calendar needs to be reformed.
He then presents two main arguments defending the current status of the
calendar against any proposed reforms. The main points are (my paraphrasing):
(1) Having Pesach after the equinox is only a sufficient but not a
necessary condition for inserting an extra month. Rambam in Kiddush
HaChodesh 4:5 writes that the Beit Din could add an extra month
"because of necessity" for seemingly minor communal needs (such as
the roads being too wet for the Jews to travel to Jerusalem for the holiday).
So it is clear that the calendar allows for leap years even when Pesach
will end up more than a month after the equinox, and an important
"communal need" in our time is to preserve the integrity of the current calendar.
(2) Rabbinic enactments in general are based on reality as viewed by
the Rabbis at the time of the enactment. If after time the reality
or our understanding of it changes, the old "din" (law) remains.
The Rabbis who fixed the calendar determined a certain approximation
to be used as the "spring equinox for the calendar", which approximated
reality very closely around the time of Hillel II (around 4119 / 359 CE).
The gradual drift of this approximation from the true equinox over the
centuries is no reason to change the halakha as determined by the Rabbinic approximation.
Mr. Loewinger seems to appreciate questions about the calendar, so if
you e-mail him any questions or comments at the address below I'm sure he
will be happy to answer. (You can tell him you heard of him from me.) He
does speak and write English as well as Hebrew, so you can write to him in
either language. Maybe you can even prevail upon him to write an English
translation of the article. He actually wrote a whole book on the same
topic (193 pages, in Hebrew) the last time we had such a late year (19
years ago, 5746), called "Al HaSheminit". It's now out of print, but I've
been able to obtain a photocopy of it, and I have read through parts of it
and I hope to do a more thorough job over Pesach.
I hope this is of interest. I have not told Mr. Loewinger of your
respective websites, but I'm sure if you do he will enjoy looking at
them.
Please do not blame him for any errors caused by my paraphrasing of the
main points in his article.
Wishing you a chag kasher vesameach,
-Ari
-----------------------
Ari M. Brodsky
ari.brodsky@utoronto.ca
Yaaqov L o e w i n g e r - civ.eng.
mail : P.O.B. 16 229 ; 61 161 Tel Aviv / Israel
e-mail : judithl@post.tau.ac.il
====
Date: Mon, 18 Apr 2005 13:36:00 -0400
From: Irv Bromberg
Subject: Yaaqov Loewinger's Recent Article on 5765
Ari and Remy:
Thank you very much, I will undertake to study the document that you
attached.
One does not need fancy astronomical algorithms to realize that the
Hebrew calendar is drifting with respect to the solar year at a rate
that is second only to the Julian calendar. Just compare 19 x the
March Equinoctial year length (or, for that matter, the mean Gregorian
year length is close enough) with the duration of 235 lunar cycles = 19
Hebrew years. That gives a close enough estimate of the drift rate,
which has been known for over 500 years.
Papers like Loewinger's help answer the question: If the drift rate
has been known for so long, why hasn't anything been done about it?
There will always be people like Loweinger who find ways to justify
continuing the status quo, which is of course always easier than making
any change. If not corrected then Passover will drift into summer time
and there will still be authorities who will find reason not to change
anything. That is why we will still be at the sedar table at 2 am next
weekend (one hour earlier in Israel, due to their earlier sunset time).
What I want to learn is how to present an argument for calendar reform
which will be persuasive for rabbis.
The usual obstacles that I encounter with rabbis are:
- Who cares? In the year 6000 the Meshiach will come and so we don't
have to worry about changing anything!
- Too busy to listen
- Not interested
- Can't understand astronomy / science / math -- actually I have found
that this a refusal to understand rather than an inability, since any
ordained orthodox rabbi surely has the necessary intellectual capacity
- Occasionally there are those who refuse to believe that my studies
are valid, but when I attempt to show support from the work of others,
they tune out.
My own web site is much too complicated for rabbis, but I haven't had
time to do anything about it. It would be best to collaborate directly
with a rabbi who is committed to the cause and will help me present the
material in an appropriate way.
I invite both of you to try out my new major update of "Kalendis"
(freeware calendar calculator for Windows) -- I posted version 8.0(555)
last week, with significant zmanim report improvements and a new button
in the Hebrew calendar window that shows Hebrew calendar cycle details.
The locale named Toronto (ZS-LWM) corresponds to the GPS coordinates
of the Zichron Scheur - Lakewood Minyan on Bathurst just south of
Glencairne, and "BYAD" has the coordinates of Beth Jacob V'Anshe Drildz
synagogue on Overbook at Wilmington.
-- Dr. Irv Bromberg, University of Toronto, Canada
Date: Mon, 18 Apr 2005 03:18:55 -0700 (PDT)
----Remy Landau replies
Dear Ari,
Thanks for bringing this article to my attention. I hope that Yaaqov Loewinger
will make available an English version of this interesting article.
It is known that Pesach is not actually geared to either the vernal
equinox, since this was never in the Torah language, and decidedly not
to the phase of the moon, as so commonly mistaken by the Christians who gear
their Easter to the first full moon on or after the first Sunday on or
after the vernal equinox. (And their Eastern Orthodox counterparts who
gear it to that event, unless of course it is before Pesach in which
case it is postponed to the first Sunday after Pesach... hence the May
1 date this year for the Eastern Orthodox Christians).
However, the very latest Pesach's, based on the fixed Hebrew calendar
will always occur in the 8th year of the mahzor qatan
simply because (12*9 +5) mod 19 = 18.
Also, because the Hebrew calendar drifts through the astronomical realities,
only its reform will correct that problem, assuming that this drift does indeed
present a problem.
Hag Sameach!
Remy Landau
====
Date: Mon, 02 May 2005 16:47:51 -0400
From: Larry Padwa
Hi Ari,
.... I'd appreciate it if you could send me a copy of the article.
If you could send both the original Hebrew and your English translation
that would be best. Failing that, either will do although I'd prefer
the English.
Thank you very much.
Larry Padwa
Date: Wed, 20 Apr 2005 13:47:42 +0000
From: J.P. Mayer
Subject: When Does the Hebrew Calendar Day Begin?
Hello Remy,
I found it fascinating to read about the calendar. I didn't know
that things could get so complicated in such an innocent way. I have a
question for you and in my mind, it is about the Hebrew calendar or calendars.
I have been following a web discussion board and as such got
involved in responding to some opinionated (not that I would be opinionated, ha ha
ha!) posts. This one has me stumped.
It is all about a Christian discussing the Jewish calendar to make it
fit his theories about what he reads in the bible.
It is a bit complicated but here is the jist of it. He claims that
there were two simultaneous calendars in use at the same time during the time
of Christ, 2000 years ago. (I'm OK with this since we have lots of
calendars in effect in the world now). He says that one group reckoned the day to
start at sunrise and the other group reckoned the day to start at sunset. (We
have this happening now in the world, I'm OK with that).
Here is where it gets complicated.
One group ( G ) starts the day at sunrise on Nissan 15 for example.
The other group(J) starts the day at sunset but the sunset towards the end
of the G group's Nissan 15. In essence what he is saying is that during
the sunlight hours (when everyone is out and about) the daytime is Nissan
14 for one and Nissan 15 for the other.
I mentionned that this would not make any sense to live, to actually
have to live this way and that the sunsetters would have Nissan 15
start the previous night so that the daylight hours would correspond
and this way the calendar is not in the way of social conventions.
I asked what happened during the Sabbath when someone could claim to be a
sunriser and work or vice-versa. He answered that it was an accepted
convention at the time.
In my mind this person is making the world fit his interpretations of
the bible instead of the other way around. I may be wrong but am I barking
up the wrong tree when I challenge him on this?
Hope you have come across something in your research that can help me
figure this one out.
Many thanks if you can respond. If you cannot, I understand because
this is quite unsollicited on your part.
In friendship,
J.P. Mayer, Sudbury Ontario Canada
Date: Wed, 20 Apr 2005 15:55:21 -0700 (PDT)
----Remy Landau replies
Dear J. P. Mayer
When in doubt over the facts it is always a good practice to have some
reference to the sources which underlie the conclusions.
Now, with regards to Jewish practice, the day appears to have always
started at, or soon after, sunset. The reason for this tradition lies
in the magnificent refrain found in Bereshit I (Genesis I)...
*vayehhi erev Vayehhi voker..* "...and there was evening and there was morning
..." (on that day)... so it was concluded, quite traditionally, that
the day began at, or near, the sunset.
We now come to another interesting practice.... the Shacharit service,
which is the morning service. Some of the very religious like to
perform this service at, or near, the crack of dawn. However, this does
not override in any way the fact that the day began the previous night.
With regards to Nisan 15... that is the first day of the Pesach festival,
and it begins after sunset on the previous evening.
Some religious groups insist that the Seder ritual not begin until
after the darkness of the night of the 15th has set in.
Most Seders begin after dark anyways...
So, until your friend can clearly identify the historical, and
archeological sources on which the dispute appears to be based, it is
not be possible to make any particular claim of authencity with
regards to the sunrisers.
Hag Sameach!
Remy Landau
Date: Fri, 22 Apr 2005 18:20:28 +0100
From: Dr John Stockton
Subject: Which Day Begins the Jewish Week?
In Mail message
Date: Tue, 26 Apr 2005 08:12:33 -0500
From: Michael Koplow
Subject: Sefirat Ha'Omer Technique
Dear Remy Landau.
I am in awe of your calendar web site. I got a BS in math many years
ago. I've never had a job relevant to math, and my skills have largely
gone away, but I'm still geeky enough to noodle around with math. I'll
sometimes copy an article from the Journal of the American Statistical
Assn and try to work my way through it -- working my way through your web site
is going to be one of my next projects. Thank you.
Anyhow, here's something very simple. Let's say you have a siddur that
tells you what to say on the nth day of the omer, but you don't have a
chart for the current year that tells you what day you're on. Here's
what the sticker in my siddur says: "April--date minus 23; May--date + 7;
June--date + 38."
I've done something like this for several years now, and I've proven to
my satisfaction that the following formula works (the months are
gregorian):
month 1--date minus a; month 2--month + b; month 3 (if there is a third
month)--month + c, where a = date of 2nd seder minus 1, b = number of
days in month 1 minus a, and c = b + the number of days in month 2.
Kids' stuff compared to what you've published, but useful nevertheless.
Thank you for the web site.
Moadim LeSimchah, and be well.
Regards,
Mike
Date: Tue, 26 Apr 2005 07:56:49 -0700 (PDT)
----Remy Landau replies
Dear Michael
Good work on the Omer....
The constants you gave are quite correct for this year... and the
variables, at first sight seem to lead to the right offsets based on
the Gregorian date of the first day of Pesach.
When you analyze the math of the web page... please be kind in the
criticism... there are considerable improvements which have come to my
attention since first paged ... and one day it will be improved. I'm
still working on that now. There are two major streams involved... one
is the purely theoretical stuff as given by Gauss... and the other is
the digital technical stuff needed to push the digital barriers thrown
in by the computer.
Haggim U'Zemanim L'Sosson!
Remy Landau
Date: Thu, 28 Apr 2005 21:59:43 +0530
From: Shriramana Sharma
Subject: Hindu Calendar
I am a member of CALNDR-L and had a look at your Hebrew calendar via a
link posted by one of the list members. I do not profess to have
grasped and digested all the information on your page, but I can see you
have done extensive and painstaking work and hence felt that you certainly
deserve much commendation. Many congratulations!
I am working on updating my Hindu calendar pages and will inform you,
if you tell me you are interested, when they are ready. Hindu calendars
use perfectly astronomical *definitions* (though historically they used
different algorithms for astronomical calculations). So my pages will
not contain as many intensive calculations as yours, since I expect the
latest astronomical formulae to be used, instead of ancient
approximations.
Shriramana Sharma
http://samvit.org
Date: Thu, 28 Apr 2005 14:29:11 -0700 (PDT)
---- Remy Landau replies
Dear Shriramana
Please do keep me informed of the calendar information that you are
preparing.
And thank you for the good wishes.
Hag Sameach!
Remy Landau
Date: Sun, 8 May 2005 08:41:49 +0100
From: Steve Winnitt
Subject: The 360-Day Year Calendar
Hi Remy,
I am interested to know why many Christians believe the Ancient Hebrew year to be 360 days. Where do they get this idea?
I look forward to your reply,
Thank you
Steve
==== Remy Landau replies
Date: Sun, 8 May 2005 05:14:02 -0700 (PDT)
Dear Steve,
This inquiry is well beyond my knowledge levels of the Hebrew calendar.
I am aware of some speculation at the scholarly level as to what some
of the solar and lunar calendars might have possibly looked like back
in ancient times. The 360-day year calendar has been part of that
speculation. However, no scholar has ever been able to prove that such
an anomaly was actually ever used by anyone.
Hodesh Tov!
Remy Landau
From: Ari Meir Brodsky
Subject: Yom HaAtzmaut's Moving Target Date
Date: Tue, 10 May 2005 01:59:25 -0400
It's that time of year when we start thinking about the Calendrical
Complications of Yom HaAtzmaut. Well, some of us do, at least!
Some highlights regarding this year's Yom HaAtzmaut:
YOM HAATZMAUT ADVANCED TO 3 IYYAR: Because 5 Iyyar falls on Shabbat
Knesset law stipulates that Yom HaAtzmaut is celebrated on the
previous Thursday, 3 Iyyar, and Yom HaZikaron is observed on Wednesday,
2 Iyyar. See the relevant legislation at
www.knesset.gov.il/laws/special/heb/chok_yom_haatzmaut.htm and
www.knesset.gov.il/laws/special/heb/chok_yom_hazikaron.htm .
My understanding is that this adjustment has been in effect for as long as
Yom HaAtzmaut has existed. (DOES ANYONE KNOW IF THIS IS CORRECT?)
This year is the 8th time in history that we celebrate Yom
HaAtzmaut on 3 Iyyar. The first one was 5710 (1950).
This year is a late-year (Jewish calendar dates and holidays are as late as they
get in the 19-year cycle, relative to the solar year), so the anniversary of
Israel's Independence - 5 Iyyar - actually falls on May 14 this year,
as it did in 5708 (1948) and 5746 (1986).
There are many other calendrical features of this holiday that I would
love to research and write about if I had an infinite amount of time and
weren't working on a Ph.D. thesis.
==== Remy Landau replies
Date: Tue, 10 May 2005 05:37:07 -0700 (PDT)
Dear Ari...
Good email...
Much to think about...
Minor detail...
In our times the absolutely latest observance of the biblical festivals
will begin on April 25, 2043... Not on April 24...
And of course 1 Tishrei that year will be October 5.
After that, check The Rosh Hashannah Drift...
Date: Tue, 17 May 2005 20:55:54 -0700
From: Clark Wilkins
Subject: Babylonian Period Hebrew Calendar
Hello.
Before the Babylonian calandar was adopted, what calendar did the Hebrew use?
Was there a period when both calendars were used? If so, for how long?
My curiosity would be whether or not there would have been an argument over
when to hold the feasts during the period of overlapping calendars?
Thanks.
Clark
==== Remy Landau replies
Date: Sun, 22 May 2005 07:17:13 -0700 (PDT)
Dear Clark
Are you assuming that the the Hebrew calendar came out of Babylonia?
It's not really certain as to what type of calendar system would have
been used by the Jewish people at the time of Babylonia's supremacy.
Even Parker and Dubberstein (1942) who did pioneering work through some
exhaustive archeological Babylonian records had difficulties in
establishing the actual calendar system used by this civilization and
when it first came to be systematized.
The Jewish people appear to have relied on some method of lunar
observation, coupled to some type of unknown calculations, in
determining the starts of months and years before they published the
fixed Hebrew calendar rules possibly as early as the 4th century CE.
The fixed Hebrew calendar rules, as known to us today, do not seem to
have emerged until sometimes in the early 10th century CE. (See Sacha
Stern's Calendar and Community - Oxford Press 2002).
In terms of overlapping calendars (as you seem to suggest), Talmudic
Tractate Rosh HaShannah at 25b pretty much defines the calendar
authority... and in Talmudic times that authority was decidedly in
rabbinic hands and nowhere else to be found. Thus, the Jewish
determination of a particular festival date lay solely in the hands of
its religious leadership, and not in any foreign methodologies. In
other words, if the rabbis decided that today was Yom Kippur, then
today would be Yom Kippur.
Shavuah Tov!
From: Dwight Blevins
Subject: Plucking Harps and Calendar Cycles
Date: Fri, 3 Jun 2005 08:21:46 -0600
Dear Remy,
Sorry I've been out of contact for so long. We've been moving the
offices and plant of the harp facilities, which chore seems to be
endless, as we started in March and shall apparently not finish until
late summer.
In any case, I was following the recent discussion of the 43 year
maximum span, when again wheels turned within wheels (as they are wont
to do), and a question of connected artifact did arise.
The holdout, bookend to the pattern, being the 384 day year (ie, which
would fall at year 44 of the span), is indeed unique in that it can
ONLY begin on the weekday of Tuesday. Somehow, this is a symmetrical
thing of curiosity, which also results in the precise occurrence of
36,288 times (1/19th) per full HC cycle. This we know, as you have
well documented on the website.
But, here is the point to which I leap. Of the 36,388 times that the
384 day year occurs, how many the 384 day years are created by
postponement? Is there a more or less direct relationship of the
61/39% ?? I guess the question, more precisely would be, are ALL
lengths of lunar years created by postponements about 61% of the time
for each example of year length? That is, would the 384 day year be
created by postponement about 0.61 x 36,288 = 22,136 times, per 689,472
year HC circle?
I'm particularly curious, since I believe few things in mathematics are
accidental. As you have well said (at some point in the past), the HC
has been based mainly on the laws of symmetry and little else. So, I
am automatically suspicious as to why (if so) 61% of 36,288 falls out
fairly close to a Biblical number of coincidence. That would be 22,
273, which is not far removed from 22,136. Of course, 22, 220, 22,000,
etc., is number sequence fairly connected to Hebrew, symmetry, and the
scriptures.
Please tell me if my curiosity makes any sense at all? If so, I shall
be happy to tell you where I found the number 22,273, which sums to 16,
the mirror image of 61, and just happens to fall out fairly close to
61% of 36,288. Always happy to help you stir the pot, just a little
bit more, attempting to make all the circles round :)
Dwight Blevins
====
Date: Sun, 5 Jun 2005 08:24:24 -0600
From: Dwight Blevins
Subject: Plucking Harps and Calendar Cycles
That my last question does not have logic in mathematical fact. That
is, the postponement effect is cumulative, adding up to about 61%.
Therefore, it does not seem that any one declaration could be postponed
anywhere near 61% of the time. Nevertheless, I shall wait and
appreciate your comments, as my logic oft contains blind spots :)
But, Tuesday, being influenced by rules 2 (adding 14.2857, or 1/7th),
and rule 4 (adding only 0.54%), it seems likely that less than 15% of
the 384 day years are postponed.
Something of interest that I did realize, as a result of asking the
question, is that Saturday, the seventh day, is the ONLY day of Tishrei
1, that is influenced by ONLY one postponement rule (ie, #2), and that
precisely 1/7th of the time, making the frequency exactly 2/7ths (as
your website states). All other days of declaration are influenced by
at least 2 postponement rules. So, Saturday seems to be unique in this
regard, as compared to the other 3 weekdays of declaration. Monday
seems to have been honed to exactly a multiple of sevens (by percentage
of 28%), making it some sort of symmetrical reference point of mark.
Best Regards,
Dwight Blevins
====
From: Dwight Blevins
Date: Sun, 5 Jun 2005 10:03:15 -0600
Subject: Plucking Harps and Calendar Cycles
Dear Remy,
Apparently, without realizing it, you pluck the strings quite
frequently. The pattern symmetry of 3323332 is, after all, the exact
replication of what musicians call "the progression of a major scale."
The scale, in the natural form of progression (called, key of C), runs
the course, Tuesday through Monday, or C-B, or 1-7. This is the only
sequence which has no interruption of "sharps," being purely diatonic.
So, by progression of the sevens, it is
long-long-short-long-long-long-short, or 3323332. Simple, eh?
Thus, is can be seen, by the patterns of symmetrical law, that the 7
day Tishrei loop, circle, or cycle, runs Tuesday-Monday, or 3-2--the
end of the cycle being adjusted by rule 4, which, sometimes being
chopped early, bumps the declaration forward to Tuesday, while the
beginning of the cycle (Tuesday) is sometimes chopped late, or delayed
(rule 3), moving the point forward to Thursday.
In any case, the circle calibration being kept in check, by the
whick/whack of rules 3 and 4 = 3.31 + 0.54 = 3.85%--an exact multiple
of sevens, which the weekly circle contains 385/7 = 55, which 4th
multiple is 220 hertz, note A of the 4th or middle C octave, home point
of the "progression of a major scale."
Can you imagine the scheduling mess created for the 24 courses of the
temple service, if this hacking and whacking had occurred at
Friday-Saturday instead of Monday-Tuesday? Not nice, therefore the
sages of symmetry of the Bet Din probably liked the 2-3 or 3-2 tweak of
Monday-Tuesday, much better.
This concludes the little discourse from the Blevinski spin zone. Now,
back down on the farm, continuing to whack away at them harps.
Dwight Blevins
==== Remy Landau replies
Date: Sunday, June 5, 2005, at 09:06 AM
Dear Dwight
You have made my head spin... and I get a lot of unsuccessful
attempts at that!
Your musings are sufficiently delightful to let others attempt replies.
Shavuah Tov!
Remy Landau
Date: Fri, 3 Jun 2005 14:20:42 -0400
From: Noam Kaplan
Subject: The Molad of Sivan 5765H
Dear Remy,
Thank you for your Hebrew Calendar calculations website. Can you tell me
what is meant by the time of the molad?
I understand that the molad is a calculated time based on the mean time
that it takes for one lunar cycle.
I also understand that the hours that are used are standard 24 hours per day hours,
not temporal hours, with the day starting at the night.
What does this mean?
The molad of Sivan 5765H will occur on Tuesday at 13h 52m 8hl.
Where and at what time on our clock?
Thanks for your time,
Noam Kaplan
PS: I have a calendar up at
http://www.riets.edu/stuff/zman/month.asp
that I am currently working on.
==== Remy Landau replies
Date: Fri, 3 Jun 2005 12:38:09 -0700 (PDT)
Dear Noam,
The molad is the name given to a particular value calculated in a
particular manner.
The value at one time was meant to represent the ideal time of the new
moon in terms of some particular reference point. Different people
today will give you different ideas as to where that ideal reference
point might be.
So today, when we say that the molad of Sivan 5765H is 13h 52m 8hl we
are saying only that this is the value given in accordance with the
fixed Hebrew calendar method as defined more than 1,000 years ago.
In so doing, we are remained spiritually linked to the many generations
of Jewish scholars that have preceded us. To me, that is far more
important than any astronomical event.
Shabbat Shalom!
Hag Sameach!
Remy Landau
PS... Your calendar is excellent work and has now become one of my personal
reference links.
It was nice to hear from you and to review some of the more prominent
highlights of the Hebrew calendar calculation history.
I'll do my best to answer any other question you might have on this
subject.
Hag Shavuot Sameach!
Best Regards
Remy Landau
Date: Mon, 20 Jun 2005 14:18:03 -0000
From: George Thlick
Subject: Calculating the Molad of Tishrei 3790H
Mr. Landau,
Thank you very much for your article on the science of the Hebrew
calendar, which has given me a better understanding of the subject.
I have a question on the calculations of the Molad of Tishrei 3790H,
using Wolfgang Alexander Shocken's formula on the top of page 6
of 25 in your article. I understand that the Molad of Tishrei is
the new moon of Tishrei, or the 1st day of the month of Tishrei.
If I am wrong, please correct me.
For 3790H, I am following the calculations of your example on the top
of page 7 of 25 in your article:
INT (235 * HY -234) / 19 = (235 * 3790 - 234)/ 19 = 46864.00
Then 46,864 * (29d + 12h + 793p) = 1,383,921d 18h 352p
Adding BaHaRad of 2d 5h 204 shown on page 6 of 25 to the above product:
1,383,921d 18h 352p + (2d 5h 204 p) = 1,383,923d 23h 556p
Dividing 1,383,923d by 7 leaves a remainder of 2.
On the top of page 4 of 25 of your article, a remainder 2 means the
1st day of Tishrei 3790H is Monday.
But when I entered 1 Tishrei 3790H into Fourmilab's calendar converter,
it showed that 1 Tishrei 3790H fell on Tuesday.
I would like to hear your thoughts on the reason why 1 Tishrei 3790H falls on
Tuesday using Fourmilab's calendar converter, and
on Monday using Wolfgang Shocken's formula.
Thank you very much for your time.
George Thlick
==== Remy Landau replies
Date: Mon, 20 Jun 2005 08:52:44 -0700 (PDT)
Dear George
There is a difference between the day of the molad of Tishrei and the
the 1st day of Tishrei. In some situations, these two days are the
same. But in about 62% of the cases these days are different due to the
DEHIYYOT.
Since the molad of Tishrei 3,790H is 2d 23h 556p, and the preceding year was
a 13-month year, the applicable dehiyyah (or postponement) is B'TUT'KaPoT
(ie postpone to a Tuesday if the molad of Tishrei after a 13-month year is on a
Monday later than 15h 588p).
Consequently, 1 Tishrei 3790H (Tue 25 Sep 29g or 27 Sep 29j) fell on Tuesday.
Other than that, your calculations are correct.
I hope that this explains your results.
Shavuah Tov!
Remy Landau
Date: Wed, 6 Jul 2005 11:06:16 EDT
From: Marshal Portnoy
Subject: The Start of Tishrei in The Gregorian Year
Dear Mr. Landau
I just wanted to let you know how much I enjoy your discussions of
the Hebrew calendar. I see that the next machzor will begin
in 2015 right in the middle of September.
Going back, I noticed that the last several machzorim also occur
on the 13, 14 or 15th of September.
I'm not sure what it signifies (probably nothing!), but I found it interesting
that the machzor of the Hebrew calendar seemed to coincide
with the "midpoint" in its correspondence to the Gregorian calendar.
Marshall Portnoy
Philadelphia
Date: Thu, 7 Jul 2005 14:37:46 -0700 (PDT)
==== Remy Landau replies
Dear Marshall,
The 19th century mathematical genius Carl Friedrich Gauss noted
that the point of the month in which Tishrei started could be given as
base date + ((12*HY + 5) MOD 19) * (29d 12h 793p) / 19.
That effectively leaves the start of a Hebrew year in our times
anywhere from September 5 to October 5.
Note that when HY is of the form 19*k + 9, as it will be for the year
5766H, then the formula cited above yields the maximum possible value,
namely 18 * (29d 12h 793p) / 19.
And that's why 5766H will begin very near the end of the maximum
possible date currently for Tishrei 1.
Check out the year 5758H which started on October 2... and the year
5777H which will start on October 3.
That is very consistent with the Gaussian formula mentioned.
I'll let you see for yourself what happens in 5774H.
Shalom!
Remy Landau
Date: Sun, 10 Jul 2005 18:26:12 EDT
From: Marshal Portnoy
Subject: Hanukah, December 25, and Hebrew Month Names
I have two more questions...
(1) Do you think there is any relationship between Kislev 25 and December 25?
(2) What months are specifically mentioned and not mentioned in Humash?
Thanks,
Marshall
Date: Sun, 10 Jul 2005 19:12:59 -0700 (PDT)
==== Remy Landau replies
Dear Marshall,
1) the relationship between Kislev 25 and December 25 is very much tenuous, if at all.
After a while, if nothing is changed in these two calendars, Hanukah
will be somewhere in January. This phenomenon is documented in
The Rosh Hashannah Drift.
2) Tanach is rather spotty in regards to the calendar. It makes reference to
the first month, the 7th month, and the months of Aviv, Zif, Ethan and Bul.
A complete set of the months' names can usually be found in other web sites using
a variety of the internet search engines.
Shavuah Tov!
Remy Landau
Date: Tue, 12 Jul 2005 16:31:28 -0400
From: KosherJava
Subject: Hebrew Year Number Transliteration
Remy,
I greatly enjoy your site. In the Correspondence, I noticed a
request by Giora Magen for Hebrew Year Number Transliteration.
Such code does exist. It was developed as part of the Hebrew date support in PhpGedView,
an online genealogy viewer found at
http://phpgedview.sourceforge.net/
To allow the code to be used by a non programmer, I ported the code to
Javascript and posted it at:
http://www.kosherjava.com/2005/07/12/hebrew-year-conversion/
Date: Tue, 12 Jul 2005 19:21:10 -0700 (PDT)
==== Remy Landau replies
Dear KosherJava,
Absolutely amazing!
Thank you !!
====
To: GIORA MAGEN
CC: KosherJava
FROM: Remy Landau
Dear Giora,
Your February request was noticed by correspondent "KosherJava" who
advised me of the solution.
I believe that it may perhaps be what you are looking for, and so I'm
suggesting that you might be interested by the recent correspondence
found above.
I hope this will satisfy your request.
Shalom!
Remy Landau
Date: Wed, 13 Jul 2005 11:05:47 -0700 (PDT)
From: Lydia Esther
Subject: Request for Historical Hebrew Calendar References
Hi,
Came across your piece on the internet regarding the Hebrew calendar - numbering,
dates, leap year etc.
My question is why in the religious calendar are pagan terms being used - i.e.,
the month of Tammuz, of which "we're in' now. Also, after much prayer and
research - I do not believe we're at the year it's said we are right now,
but much closer to the 6000th year point.
Any suggestions on whom to turn to for answers? I would greatly
appreciate it.
Your response to these questions would be greatly appreciated at your earliest convenience.
Our YHVH is a jealous Yah!
Thank you,
Lydia Esther
Date: Wed, 13 Jul 2005 12:30:10 -0700 (PDT)
==== Remy Landau replies
Dear Lydia
Since the Hebrew calendar material shared is largely of a technical
nature, rather than either historical or religious, your questions
address an area of studies that is well outside the scope of the
subject matter.
You might start with the works of Parker and Dubberstein on the
Babylonian calendar... it is a bit dated but they did do expert work on
the subject.
You might also try the more recent Calendar and Community by Sacha
Stern...
Shalom!
Remy Landau
Date: Thu, 18 Aug 2005 12:28:56 +0300
From: Dvir Gassner
Subject: Free Hebrew Calendar Software for OUTLOOK
Hi Remy,
I have recently created a software for incorporating Jewish dates and holidays
into the Outlook calendar.
I think it might be useful for your visitors.
This Jewish calendar tool is free, of course.
I was wondering if you'd like to add a link to it from the
Hebrew Calendar Related Links section of your site?
The url is Jewish Calendar for OUTLOOK
If you have any questions please don't hesitate to contact me.
Thanks,
Dvir Gassner
Date: Sun, 21 Aug 2005 12:47:41 -0700 (PDT)
==== Remy Landau replies
Dear Dvir
This will certainly be useful to any reader who uses the Outlook
software.
Thank you for providing the link for shared use.
This will be mentioned soon.
Shavuah Tov!
Remy Landau
Date: Sun, 21 Aug 2005 12:40:08 -0400
From: Ezra Lwowski
Subject: Thank you!!
....for your calendar website. It is wonderful.
Ezra S. Lwowski, PhD, MBA
Date: Tue, 23 Aug 2005 03:20:28 -0400
From: J. Neidich
Subject: Blessing of the Sun..?
I READ THE BLESSING OF THE SUN - BIRCHAS HACHAMAH IS RECITED ONCE EVERY 28 YEARS BECAUSE
IT IS BELIEVED THAT IN EVERY 28 YEARS THE SUN RETURNS TO ITS PLACE AT THE TIME OF CREATION.
CAN YOU EXPLAIN IN SIMPLE TERMS THE MOVEMENT OF THE SUN And HOW IT MOVES
EACH 28 YEARS.
I DON'T KNOW MUCH ABOUT THIS BLESSING OR THE NATURE OF THIS MOVEMENT OF THE SUN.
THANKS!
Date: Tue, 23 Aug 2005 03:05:22 -0700 (PDT)
==== Remy Landau replies
Dear J. Neidich
The Ptolamaic model of the universe had the sun circling the earth. This
model was used by practically almost all of the medieval sources.
The Julian calendar, and the Rab Shmuel system of computing the
tequfot, i.e., the start of the seasons, had the time of the sun's
annual circuit around the earth exactly equal to 365d 6h.
Extending this neat little fraction a bit further, then every 28 years,
the start of a particular moment in the sun's circuit would be, over the earth, at exactly the same point in time (right down to the week day) as the initial
departure point when that theoretical clock got started 28 years earlier.
Thus was born the idea behind the Birqat HaChamah.
Of course, there was a competing idea. Rab Adda suggested that the
annual solar period was actually a bit shorter and more equal to one
nineteenth of 6839d 16h 595p. And so was born the second method of
computing the tequfot. This alternate calculation was not popular,
possibly because it involved a much more cumbersome fraction than did
the Rab Shmuel numbers.
It has to be understood that at the time of these competing ideas, the
western astronomers had pretty much fixated on 365d 6h as the duration
of the annual solar period. In fact, that timing was the fundamental
basis of the Julian calendar's construction.
Thus, the concept of the sun returning to its very same place in every
28 years, as might be suggested by the commentaries on Birqat HaChamah,
has no particular basis in any scientific fact.
However, in terms of the rabbinic halachah, reciting the Birqat HaChamah
once in every 28 years is a valid custom.
Shalom!
Remy Landau
Date: Tue, 23 Aug 2005 23:37:26 +0000
From: Karmen Williams, Ed.D.
Subject: The Significance of Enoch's Age?
Respectfully, I would like to know if there is special significance
in the age of Enoch (365 years) when God took him.
I have been reading online correspondence about the Hebrew calendar and wonder
if there is any significance to Enoch's age of "departure".
Karmen Williams, Ed.D.
Date: Tue, 23 Aug 2005 20:47:29 -0700 (PDT)
==== Remy Landau replies
Dear Karmen
Some bible scholars have suggested the possibility of significance of
practically any and all numbers specified in the biblical narratives.
And some scholars have even ventured highly speculative ideas
concerning these numbers.
For example, the fact that Joseph lived 110 years instead of 120 has
led traditional rabbinic literature to suggest that the 10 years removed
were because of the ten times that he denied his origins to his
brothers in Egypt.
Some scholars have looked at Enoch's age as proof that a solar calendar
of 365 days had originally been used by the Hebrews.
Personally, I could be very silly and suggest that because Sarah lived
to be 127 years old, they had computers in those days since 127 is, in
binary, a string of seven ones, ie, 1111111.
Also remarkable in the biblical age telling is that the Mosaic text
records a life span of 137 years for Ishmael, Levi, and Amram (the
father of Moses). Surprisingly, no commentary is found on this
particular triple coincidence.
Returning to your question, the answer is most likely negative.
However, it may also be a positive one, in which case the reasons of
the significance also would have to be stated. I'm not at all convinced
that anyone has actually provided any such credible reasons.
Shalom!
Remy Landau
Date: Mon, 29 Aug 2005 10:43:39 +0200
From: A. Zoltan Varga
Subject: Next Hebrew New Year Start?
Dear Remy,
I would like to know when the Hebrew New Year begins
in the coming days?
Thank you very much.
Zoltan
Date: Mon, 29 Aug 2005 02:57:37 -0700 (PDT)
==== Remy Landau replies
Dear Zoltan,
Hebrew year 5766H will begin at sundown on Monday 3 October 2005g.
That represents the start of Hebrew day Tuesday, because the Jewish day
always begins on or after sunset. This is an important idea because the
molad of Tishrei 5766H is on Monday at 16h 48m 12hl
and therefore the 1st day of Tishrei 5766H has to be postponed to
Tuesday in accordance with the postponement rule known as Dehiyyah
B'TU'KTPT.
For more information on the postponement rules please see
The 4 Dehiyyot (Postponement Rules)
Shalom!
Remy Landau
Date: Mon, 05 Sep 2005 16:05:38 -0400
From: Morris Jesion
Subject: Qeviyyot Like 5766H Between 5741H and 5752H?
Dear Remy,
How many days are there in year 5766H?
The question I ask every year - what are the years between 5741H and 5752H
that have the same qeviyyah as 5766H?
Thanks.
May you and your family be inscribed for a good and sweet year.
Morris
Date: Thu, 8 Sep 2005 15:18:04 -0700 (PDT)
==== Remy Landau replies
Year 5766H beginning on Tue 4 Oct 2005g has 354 days.
This is the only length possible for any 12-month year beginning on Tuesday.
Between 5741H and 5752H year 5742H (Tue 29 September 1981g) is the
only 12-month year to begin on a Tuesday.
Shannah Tovah!
Remy Landau
Date: Mon, 12 Sep 2005 00:20:57 -0400
From: Ari Meir Brodsky
Subject: B'TU'TKPT and Rare Calendar Events
Does anyone have, or can you generate by computer, a list of all
occurrences of Dehiyyah B'TU'TKPT during the complete calendar cycle of 689472 years?
The occurrences between 5001H and 7000H can be determined
from the table on page 38 of Shearim LaLuah HaIvry
by R. Sar-Shalom, but I'm wondering about the others.
It seems (empirically) that the possible intervals between occurrences are
78, 98, 169, 247, and 345 years, but I have not proven that other spans exist.
Also, can anyone disprove the claim that B'TU'TKPT is
the rarest single Hebrew calendar event?
Ari M. Brodsky
====
From: Yaaqov Loewinger
I posed the question for myself too. I have no clear-cut mathematical solution.
I used Sar-Shalom's lists, as you did.
See attached mails from Prof.( Physics) Hayyim Halpern from BIU.
---------------------------------------------
From: Prof.( Physics) Hayyim Halpern from BIU.:
Dear Reb Yaakov,
According to my calculations, in the years 4000H - 6000H, B'TU'TKPT occurred only
in the years 4010H, 4179H, 4257H,4504H, 4602H, 4849H, 5096H, 5194H, 5441H,
5519H, 5688H, and 5766H.
Hence, the gap of 247 years between successive occurrences
last occurred between 4849H and 5096.
Since 4010H was before the establishment of the fixed calendar,
5766 is only the 11th time that this postponement occurs.
Also, of the classical poskim, the Rif saw such a postponement, but not Rambam
nor the Rosh, and while the Tur saw it the Beit Yosef did not.
Bevirkat ketivah vechatimah tovah,
Haim Halpern
====
Date: Mon, 12 Sep 2005 11:08:06 +0300
From: Nachum Dershowitz
Ari Meir Brodsky wrote:
| Does anyone have, or can you generate by computer, a list of all
| occurrences of Dehiyyah B'TU'TKPT during the complete calendar cycle
| of 689472 years?
|
| ... It seems (empirically) that the possible intervals between occurrences are
| 78, 98, 169, 247, and 345 years, but I have not proven that other spans exist.
Assuming the absolute constancy of the fixed Hebrew Calendar then the
3,712 years invoking Dehiyyah B'TU'TKPT are
75 153 322 400 647 745 992
1239 1584 1662 1831 1909 2078 2156 2501 2748 3093 3340 3587
3685 3932 4010 4179 4257 4504 4602 4849 5096 5194 5441 5519
5688 5766 6013 6111 6358 6605 6950 7197 7444 7542 7789 7867
8036 8114 8361 8459 8706 8953 9051 9298 9376 9545 9623 9870
9968
10215 10462 10560 10807 11054 11399 11477 11646 11724 11893
11971 12316 12563 12810 12908 13155 13233 13402 13480 13727
13825 14072 14319 14417 14664 14911 15256 15334 15503 15581
.
.
.
687524 687693 687771 688116 688363 688610 688708 688955
689202 689300
The occurences are separated as follows
B'TU'TKPT Separations SEPARATION OCCURENCES 78 819
98 575
169 457
247 1,531
345 330
Date: Thu, 22 Sep 2005 22:55:15 +1000
From: Al Persohn
Subject: Date of Tisha b'Av 3830H?
Hello Remy,
Thank you for your webpage Hebrew Calendar Science and Myths.
I wonder if you could help me.
What is the date on the Gregorian calendar for Tisha b'Av AD 70?
Thank you in advance.
Al Persohn
Date: Thu, 22 Sep 2005 09:06:42 -0700 (PDT)
==== Remy Landau replies
Dear Al,
That date is actually unknown in terms of any of the western calendars,
including the Hebrew calendar itself.
The Hebrew calendar does not emerge in its present form until at the
very least the 10th century. So it is not possible to reflect an actual
correspondence between the Hebrew date and any other pre-existing
calendar and conclude that a historically true fact has been derived.
It is possible to formally calculate the date correspondences between
various calendars. The results must be understood as numbers coming
from the exercise of specific rules only as known at the time of the
calculations.
Formally, the date Shabbat 9 Av 3830H = 2 Aug 70g = 4 Aug 70j.
Historically, 9 Av 3830H probably may have been some day of the
year other than that derived formally.
Shannah Tovah!
Remy Landau
Date: Thu, 29 Sep 2005 21:43:36 -0500
From: Lara Aase
Subject: Date of Rosh HaShannah 5456H?
Dear Remy Landau,
Is there any way for me to find out when the High Holy Days happened
according to the Gregorian calendar in 1695?
I'm doing some research on Sephardic (crypto) Jews in New Mexico in the late
17th century, and although your website is fascinating, I don't have a
mathematical mind, so I thought I'd just ask you straight out.
Please email back if you can help!
Thanks so much,
Lara A.
Date: Thu, 29 Sep 2005 20:16:54 -0700 (PDT)
==== Remy Landau replies
Dear Lara,
Rosh HaShannah 5456H coincided with Shabbat 10 September 1695g.
This date in the Julian calendar was August 31.
To convert dates from one calendar to another, you might also want to use
the calendar converter found at Calendar Converter
Shannah Tovah!
Remy Landau
Date: Sun, 2 Oct 2005 21:59:41 -0400
From: Ari Meir Brodsky
Subject: Rare Calendrical Event for 5766H
Dear Friends,
This year, we will experience a very rare calendrical event, one that
has not happened in 78 years, and as long as the fixed Hebrew calendar
remains unchanged, will recur 247 years from now for Rosh HaShannah 6013H.
It is known as Dehiyyah B'TU'TKPT.
Dehiyyah B'TU'TKPT calls for a postponement of Rosh HaShannah
from Monday to Tuesday whenever the calculated time of the
molad (theoretical new moon) of Tishrei is on a Monday following a
leap year (13-month year) and is, or exceeds, 15 hours 589 halaqim.
(There are 18 halakim in one minute).
The acronym B'TU'TKPT is formed from the Hebrew symbols representing
Monday (Bet), 15 (Tet-Vov), 589 (Tof-Kuf-Peh-Tet).
Only about one half of one per cent of all of the Hebrew years are
affected by this calculation rule.
Here is a complete list of all occurrences of Dehiyyah B'TU'TKPT
according to the rules of the fixed Hebrew calendar, from the time that Hillel
II is traditionally said to have published its rules, until
the year 6013H (2252g).
From: Rabbi Steven S. Saltzman
Subject: Prime Numbers in the Hebrew Calendar?
Remy
What is the significance of prime numbers in the Hebrew calendar?
(This question was asked in person)
Date: Wed, 5 Oct 2005 18:34:25 -0700 (PDT)
==== Remy Landau replies
Dear Rabbi
I'm not quite sure.
The fundamental generating value of the calendar is the molad period
given as 29d 12h 793hl.
Converted to halaqim, the value becomes 765,433 halaqim = 131 * 5843,
which is not prime.
The fraction of day is 12h 793hl = 13753 halaqim = 17 * 809.
The 793 halaqim = 13 * 61.
From these values, it may be deduced that a 12-month year is
12 * 131 * 5843 halaqim,
and that a 13-month year = 13 * 131 * 5843 halaqim.
So it appears that the fundamental time units of the calendar do not
involve prime numbers.
There is the 7 day week and the 19 year cycle and possibly the 13-month year.
But these are not the units at the fundamental calculation base
of the calendar arithmetic.
Now, going off into the single year lengths in days
353 = prime number
354 = 2 * 3 * 59
355 = 5 * 71
383 = prime number
384 = 128 * 3 (the number of place settings wanted by the caterer)
385 = 5 * 7 * 11 (a multiple formed by 3 consecutive primes)
Intriguingly, only the deficient single years, that is,
the 353-day and 383-day years, have prime number of days.
Just as an aside, the year value next year will be 5767 = 73 * 79...
Incredibly a multiple of two consecutive primes.
Shana Tova!
Date: Sat, 8 Oct 2005 08:30:06 -0700 (PDT)
From: Kevin Kelly
Subject: Which are the Shabbat Days in America?
I'm researching Shabbat in America.
Because of the various time zones in America, what days of the week correspond to
Friday/Saturday in American time?
If we use the traditional Jewish Shabbath day would it be the same here
or would it be Sunday or Thursday?
Thank you for your time
Kevin B. Kelly
Date: Sat, 8 Oct 2005 18:03:37 -0700 (PDT)
==== Remy Landau replies
Dear Kevin
With regards to the start time of Shabbat, anywhere in the world with a
reasonable sunset time, it is usually set at a halachically
predetermined number of minutes prior to the local time of the sunset.
The time will therefore vary in accordance with the astronomical and
geographical realities of the particular place on earth.
With regards to geographical locations which have unusually long
periods of time between sunsets, such as the Arctic regions, or space
vehicles orbiting the planet, the Halachah here is still developing.
As far as the day of the week is concerned, that is governed by the
geographic location relative to the international date line, a concept
which doesn't emerge in western thinking until, I believe, the late
17th century. On one side of that line it is today, while on the other
side it is still yesterday (or vice versa, depending on which side you
happen to be).
Shavuah Tov!
Shannah Tovah!
Remy Landau
Date: Mon, 10 Oct 2005 19:12:44 +0000 (GMT)
From: Cloves Santos, Brazil
Subject: Request for Lunar Calendar Algorithms
Dear Remy,
I read your web page Hebrew Calendar Science and Myths.
Could you help me please?
Can you please provide me the lunar calendar algorithms, and their explanations?
I'd like to build a calendar with biblical data, and build an EXCEL spreadsheet
that will give the lunar phase for any input specifying the day, month and year.
Thank you.
Cloves
Date: Tue, 11 Oct 2005 10:19:33 -0700 (PDT)
==== Remy Landau replies
Dear Cloves
The Hebrew calendar algorithm may easily be found almost anywhere on
the web ... just Google search Hebrew Calendar algorithm or Hebrew
calendar Software...
If you look for the Gauss formula on my page you'll find a Qbasic
version of the formula which maps the Hebrew date of Pesach on its
equivalent Julian date.
If you wish to check into lunar formulas, as per current astronomical
knowledge, you'll be able to find those through a fairly simple Google
search.
Dvir Gassner has made available some free calendar software at
Jewish Calendar Software.
You might also want to check the code for the calendar converter found
at Calendar Converter
Dr. Irving Bromberg has a web site which might help you at
Kalendis
I hope that this will help you.
Shana Tova!
Remy Landau
Date: Tue, 1 Nov 2005 08:08:00 -0500
From: Irv Bromberg
Subject: The Rectified Hebrew Calendar
Remy:
Please check out my new web page on
The Rectified Hebrew Calendar
Irv Bromberg
Date: Tue, 1 Nov 2005 08:08:00 -0500
==== Remy Landau replies
Dear Irv
Awesome work!
Hodesh Tov!
Remy Landau
Date: Thu, 3 Nov 2005 14:14:38 -0800
From: Vlach, Bernie
Subject: Month of Abijah's Course?
I am trying to relate the course of Abijah's Levitical duties
to a specific Jewish month, and then to the Gregorian calendar
for the year 7 BC.
1 Chronicles 24:10 states that Abijah's course was the eighth.
Since there were a total of 24 courses, I assumed each course was for
half a Jewish month. (What happened in a leap year?)
In which month was Abijah's course? Didn't God instruct Moses to change
the Jewish calendar to make Nisan the first month of the year in rememberance
of the Passover?
Does that mean that Abijah's course was the latter half of
the fourth Jewish month (Tamuz)?
Your calendar seems to have the Jewish year begin with the month Tevet, not Nisan.
Please explain.
Bernie
Date: Thu, 3 Nov 2005 14:33:24 -0800 (PST)
==== Remy Landau replies
Dear Bernie,
The courses to which you refer were, I believe, one hour long, there
being 24 courses in one day.
There is no way of mapping the Gregorian calendar onto any Hebrew
calendar month prior to the 10th century ce. That is due to the fact
that the fixed Hebrew calendar as it is presently known did not emerge
in that form until the early part of the 10th century.
Consequently it seems quite unlikely that anyone, except for heavy
speculation, would be able to make the determinations that you are
attempting.
As for the starting point of the Hebrew year, there are four known
Hebrew new years.
The first one is Nisan 1, and is usually known as the year of the kings.
The next one is Elul 1.
Then we come to Tishrei 1 which is known as Rosh Hashana.
This is the day on which one is added to the Hebrew year count.
The year count was last updated on Tuesday 4 October 2005g, making 5766H the current
Hebrew year value.
Finally, there is Shevat 15, known as TU B'Shvat,
which is also known as the new year of trees.
We've just started the month of Heshvan.
Hodesh Tov!
Remy Landau
First Paged 25 Nov 2004
Next Revised 7 Nov 2005