Conference taveng::bagels

    Nitsan,
    
    I can't answer your questions about the calendar, but one thing I
    do know is that the the ancients knew quite a bit more about
    mathematics and astronomy than we give them credit for. In the
    time of the Bas ha'Mikdosh it was necessary for two witnesses to
    state, before the Sanhedrin, that they have "seen" the new moon.
    Once the new moon was seen Rosh Chodash could be announced. You
    can bet your last dollar (shekel) that the Sanhedrin knew the time
    of the new moon down to at least the correct minute. If these
    witnesses said that they had seen anything other than the new moon
    they would be subjected to a grueling cross examination. 
    
    Our forefathers did not distinguish between science, technology,
    and religion. The kohanim took a multi-disiplinary body of
    knowledge and used it to solve a specific problem (such as
    determining the new moon). This required great knowledge of
    science as well as of religion. Some of the remnants of this
    knowledge come down to us today as gametria, using the numerical
    value of the Hebrew alphabet to find the hidden meaning of the
    Torah. 
    
    This knowledge was paralleled by other ancient civilizations. As
    an example look at Egypt. It is a well known fact that the
    pyramids were built with a great deal of precision. Imagine the
    knowledge required to align the features of the pyramids with
    various astronomical bodies. The value of Pi (3.14...) is even
    embodied in some of their proportions. Also consider the
    technology required to move and erect the stones. And all this is
    was done for a religious purpose. 
    
    
				Fred
    

    My dictionary gives the following transliterations for the Hebrew months:
    
    	Tishri		Heshvan		Kislev
    
    	Tebet		Shebat		Adar
    
    	Nisan		Iyar		Sivan
    
    	Tammuz		Ab		Elul
    
    They remark that in leap years Adar is followed by Veadar or Adar
    Sheni.  Such a thirteen month is called "intercalary."  Any time
    period slipped into a calendar to even things up is so termed. 
    Thus February 29th is an intercalary day.
    
    Earl Wajenberg

    A lot of Hebrew calendars I've seen have had Adar I and Adar II.

Some calculations:

It takes the moon 29.5 days (how accurate is this number?) to complete one
cycle around Earth, so the Hebrew months alternate between 30 and 29 days.
For a total of 12 months we get  6*30 + 6*29 = 354 days in a Hebrew year.

Since it take Earth 365.24 days (and how exact is this?) to complete one
cycle around the sun, the Hebrew year is about 11 days shorter than the
"conventional" year.

To compensate for this, there is an extra month (Adar II), in 7 of each
19 years (in the 3,6,8,11,14,17,19-th years periodically). So every 19
years, the Hebrew date and the international date are identical to what
they were 19 years ago.

In 19 years, the difference adds up to about 213.5 days, which, divided
by 7 gives about 30.5 days (unless I made some mistake), so my questions
are:

[1] How many days are in Adar II? Is it always the same number?

[2] Does the extra Adar also compensate for the ".24" (i.e., for the 29-th
    of February) - in other words - how accurate is its number of days?

[3] With all the respect, I don't think our ancestors could know how many
    days it takes Earth to circle the sun to the 2-nd or 3-rd place after
    the decimal point. Also the numbers tend to change slightly during
    long periods of time. Was "Kislev" always in the winter? Will it always
    be? Is the 19 year match rule good also for 200*19 years ago?

[4] The modification of 7 out of 19 years is somewhat artificial. For example
    other 7 years may have been chosen. So, for example, "Yom Kipur" this yesr
    will be on Oct.13th just because the calculation was chosen to be done
    this way. Doesn't it look very strange to keep religous rules that refer
    to some exact timings (when to eat and when not to etc.) when the decision
    about the day itself is very artificial?

Nitsan,

>  Doesn't it look very strange to keep religous rules that refer
>    to some exact timings (when to eat and when not to etc.) when the decision
>    about the day itself is very artificial?

That depends on why you think religious rules are kept  in  the  first
place.   I  don't  think  that  the primary idea in Jewish law is that
there is something 'magical' about ritual, so that if  you  manage  to
fast  on  just  the  right day (Yom Kippur), God will forgive all your
sins.  That is, one form of  religious  activity  (usually  associated
with  primitive  religions)  holds  that there is something especially
effective about performing certain activities at certain  moments  and
in  certain  places.  'Effective' in the sense that the god(s) in this
world-view aren't really free to act  as  they  please,  they  can  be
forced  by  human  activity  to act in certain ways.  This is the idea
behind (for example) the sacrifice of Iphigenia (it was to  force  the
wind-gods  to  allow  the  Greek  fleet  to leave Aulis), or the human
sacrifices of the Aztecs (in order to force the gods to  provide  food
to the rest of the community).


In fact, if you only read the Bible, it is  possible  to  (mistakenly)
interpret  certain  *verses*  in  this  way,  as  saying,  "if  you do
such-and-such religious ritual, then this result is guaranteed".  But,
I  don't  think  that  even  in  the  stand-alone  Bible, this sort of
translation/interpretation  makes  the  most   sense.    Because   the
'religious  rituals'  in  these sorts of statements are really ways of
structuring society so that  certain  social  results  should  happen.
(for example, Kabed et avicha ve'et imecha, lemaan yarichun yamecha..)
[trans:  Honor your father and your mother, so that your days  may  be
lengthened...] I think it's a mis-reading to understand that as saying
that, MAGICALLY, if you honor your parents, you will have long life.


I don't think our primitive ancestors in Moses' time (or  David's,  we
can argue about when parts of the Bible were written later) understood
it that way.  A better (that  is,  more  historically  sensitive,  not
only,  I  hope, apologetically better) interpretation is to read it as
saying, "A society in which children don't honor their parents is well
on  the road to perversion and self-destruction, in which no member of
the society can hope to have a peaceful, satisfying, long life in  the
manner  in  which God wants us to live...therefore, honor your parents
(so that your children will honor you, and so that you have a  society
in  which  stable  family  life is the accepted norm, etc etc.)- under
these conditions, you can expect  to  have  a  longer  (and  certainly
happier) life, than otherwise."


Now, on to time-bound halachot.   You  have  heard,  I  am  sure,  the
description  of  halacha  --  lo  bashamayim  hi [trans:  It is not in
heaven (in the hands/control of God,  but  rather,  in  the  hands  of
man)].   By it's very definition, halacha is a system that needs human
beings to set it up,  to  clarify  and  interpret  and  formulate,  to
determine  limits,  times,  etc.   The  system  works  within accepted
procedural rules, and within a framework of having  to  be  consistent
with   moral   values   of  the  Bible,  and  within  a  down-to-earth
understanding of the possibilities and limitations of what is  humanly
achievable and so on.  But its a system that needs to be run by humans
(by its own definition!).


So, the point is not to determine  when  the  most  magical  time  for
fasting  is, in order to 'force' God to forgive us, but to establish a
communal holy day on which we pray as a community, (and also  together
as   individuals...    So,  the  *real*  requirement  is  to  have  an
established way of determining when Yom Kippur is, that is accepted by
the  entire  Jewish  community, that is in keeping with traditions and
instructions about the calender to use, etc.

Kathy

If it's the principals that count (as it should be) and not the exact timing,
then why is the government of Israel about to collapse if one of the ministers
should land in Ben-Gurion air port during (god forbid...) saturday?
Why are exact timings (to the last minute) for lighting up the candles are
published in the newpapers every week (and especially for Yom Kipur)?
Why are many holidays and other events deferred if they happen to result
in Saturday, but Yom Kipur is not?
These people who do believe that the exact day matters (and I have a feeling
there are many) - how do they explain to themselves the contradiction from
choosing the Adar II years artificially (or even from using it at all)?

just interested,
Nitsan

Note 197.4 questions the precision which could have been achieved
in astronomical measurements some 3 or 4 thousand years ago.
Astronomers of the Mesopotamian region had determined a key period
involved with cyclic repetitions of eclipses called the Saros.
Its 18 years, 10 1/3 days, or as they would have measured it
about 6584.83 days.  (I might be off a little, writing this without
reference to my science/technology reference material.)
From the eclipse observations they had this to
6 significant digits at least. Its an integral number of returns of
the moon to one of its nodes, which is one sort of lunar month.
So they could have known this month to a precision of 29.nnnn days, and
over a few hundred years of observations derived the lengths of various
other solar and lunar periodic relations to the same precision. 

Today astronomers intererested in long term variations in the
earth's rotation and other such matters give a lot of weight to the
observations of that era. If they saw an eclipse on a certain morning,
and current parameters would have made it come in the afternoon, you
get a clue on how some given rate of motion of the bodies involved
has changed. 			---MORT COHAN---

    More on ancient accuracy:
    
    Long-term observation of cycles will build fractional digits.
    
    Thus, if you count the number of full moons you see and the number
    of days you see, on one cycle you might be off by half a day.  Over
    ten cycles, you would be off at most by .05 of a day.  Over a few
    centuries you would wind up with lots of accuracy--this is because
    your observational error does not increase with time (unless you
    loose count!).
    
    All calendars are attempts to reconcile mutually prime periods:
    the day, the lunar month and the solar year.  Some calanders drop
    the attempt to keep up with the lunar month.  Julian date also drops
    the attempt to keep up with the solar year.
    
    I suspect that the position and length of the intercalary months
    in the Jewish lunar calendar were set up so as to produce the smallest
    possible deviation from the astronomical event--in that case, the
    choices are not arbitrary at all.
    
    			-John Bishop

    re .6 from Nitsan
    
    It's the principles that count, but the principle (in part)
    is to have agreed upon rules, and set agreed-upon dates and times.
    
    As to your specific points: I don't really like the politicization
    of religious behaviour in Israeli public life, but on the other
    hand I think it incredibly stupid and insensitive for a leader of
    the Jewish state to ignore basic moral/religious sensitivities common
    to at least 70% of the Israeli public, and common to most Jews for
    the last 3 or so millenia, by insisting on obviously and publicly
    travelling on the Sabbath, or eating treyf, or whatever.  
    
    I think candle-lighting times are published in newspapers 
    as a service to readers who don't have a calender handy.  Is your
    question "why have exact times in the first place"? That's part
    of the job of halacha; setting real-world limits and precisions
    to broadly (and briefly) described general outlines.  Also, shabat,
    like most things in Judasim, has significance not only as something
    observed by an individual (or family), but also as something done
    by the community.  And if you are going to have communal activities,
    you do indeed want everyone doing it at the same time.
    
    "Especially for Yom Kipur" -- as you well know, although many Israelis
    (I would guess 50%) don't light candles on shabat regularly,  almost
    everyone does on Yom Kippur. So there is apparently greater public
    interest to which the newspapers are responding.  Why is this annoying?
    
    There are halachic principles that determine when a holiday is deferred
    if it falls on saturday, and when not.  For the most part, this
    matters if observing the holy day on saturday is completely
    incompatible with observing shabat.  For example, fasting is completely
    incompatible with a couple of important aspects of shabat, so fast
    days are deferred. The exception to this is Yom Kippur, which is
    called the Sabath of Sabbaths, and which alone has this kind of
    priority over shabat. (For example, if Rosh Hashana falls on shabat,
    we don't blow the shofar, because that is forbidden on shabat (never
    mind why, for now), and even Rosh Hashana doesn't override shabat.)
    
    Anyway, I don't know that I've been very clear on all this.  My
    understanding of Judaism has always been that it is the principles
    that count, but principles, to be real, have to be translated into
    action -  into real-world ways to live real-world lives.  Principles
    don't *do* anything; they don't build the world, they don't save
    lives, they don't raise children, they don't see to it that justice
    is done.  Translating principles into action is the tricky part,
    and halacha, overall, is Judaism's expression of this translation.
    
    

Re .9:  Thanks

Re .6 (myself):  That is ofcourse "principles", not "principals"
                 (oh, my English).

Re .* (all):
------------
I wonder how do the modern interpretation of some Jewish rules solve the
problems of counting time while space-travelling, for example. When do you
light the candles when YOU ARE on the moon? Any ideas?

(I know, I know, you don't have Oxygen around there, but again it's a
 question about principles...)

Nitsan

    re .10 
    
    There is an excellent article about halacha in space in note
    75.14. 
    
    Also in your previous replies you seem to be saying that for a
    religious event to take place at the proper time, the Earth must
    be in exactly the same place in it's orbit that it was the last
    time the event was observed. Or in other words, the events should
    be timed by a solar calendar. 
    
    There is no basis for such a conclusion. All references in the
    Torah to when holidays should be celebrated are either relative to
    the beginning of the month or relative to another holiday. Dates
    in the Torah are based on the lunar calendar. There are at least
    two events based on the solar calendar (the Hebrew names escape
    me) and as a result they fall approximately on the same English
    calendar date each year. 
    
    			Fred
    
    PS - Don't worry about your English. Just think of how few of us
    here can write Hebrew. 
                           

    I thought that Passover was supposed to be in the Spring, and that
    was the reason why the holidays are prevented from drifting around
    the year.
    
    Remember, they don't call it loony for nothing!
    
    			Paul
    

    I was thinking abou Adar II again, with all this discussion about
    the calendar, and now I have another question:  what Torah protions
    are read during Adar II?  Are they all doubled up during Adar in
    years where there is no Adar II?

    re .14
    
    	There are enough Torah portions for every Shabbat that can occur
    in even the longest leap year.  The longest possible year is, I
    believe, 385 days, or 55 weeks, but bear in mind that there will
    be several Shabbatot (is that the correct plural??) which occur
    on holidays or are otherwise "special" with Torah readings that
    are not part of the normal cycle.  There are usually several Shabbatot
    where two portions are read instead of one, in order to make sure
    that the entire cycle finishes on time.  This doubling-up is spread
    out through the year, not just in Adar.  I don't know the rules
    whereby the doubling-up is assigned each year.
    
    	I became aware of the doubling-up when I realized that my
    Bar-Mitzvah portion, Tazria, occurs quite infrequently by itself,
    only in selected leap years.  That means that my Haftorah is read
    once every few years.
    
    			David

    Another interesting thing happens when a "second day" of a holiday
    which is observed outside of Israel occurs on a Shabbat.  The special
    holiday "portion" is read in "Chutz L'Aretz" (the diaspora) while
    the regular "Shabbat" portion is read in Ha'Aretz (Israel). The
    next week, the Diaspora is "behind".  It takes a few weeks, and
    some "doubling up" to bring the readings into line.  I believe this
    happened this past Shavuot.  For those people traveling to and from
    Israel during this time of parsha lagging, it causes some problems.
    
    ---Av

    Hi! I am Juan Carlos Kiel, a new employee here in Israel.
    
    I got some data for you, Nitsan, on the duration of the 
    solar year and lunar month.
    
    According to "Introduction to Astronomy", from Cecilia Payne-
    Gaposchkin, Prentice Hall, 1961. (I have a Spanish Translation
    from EUDEBA, the B. Aires University Press).
    
    Sinodic month:     29.53059 days
    Sidereal year:    365.25636 days
    Tropic(al?) year: 365.24220 days
    
    As regarding the duration of the Jewish year, I'm not sure it has
    a standard duration of 354 days, even in years without Adar Beth.
    (By the way did you know that the Yiddish designation for the year 
    with Adar Beth is "Meuberes" = Meuberet (Hebrew) = Pregnant)
    My previous statement is related to the fact that Yom Kippur CANNOT
    be on Friday or Sunday (How could you Cater for the Shabbat or the
    Fast if they would be contiguous). Therefore some fiddling around
    with the duration of the year must be allowed to compensate for
    this.
    
    As regarding the "Age" of our ritual Calendar, I would like to find
    out some comments on that but:
    a. By the beginning of the Common Era took place the Calendar reform
       of Julius Caesar and Augustus, because the EXISTING CALENDAR
       WAS NOT SYNCHRONIZED ANY MORE WITH THE SEASONS. This, in addition
       to give us July and August as month names shows both that an
       older Calendar was available and was kept for a time long enough
       to get out of synchronism and they had the tools for introducing
       corrections/compensations.
    b. I remember some Aggadah (Stories from the Talmud) telling that
       "...Raban Gamliel (a sage of the Talmudic times) order Rabbi
       Yoshua Hanapach (another sage, known as "the plumber" - showing
       that it was welcome for a Rabbi to get his bred with sweat TEMPORA
       MUTANTUR) to come to pay him a visit, with his walking stick
       and Belt (Travel indumentary) on the particular day that Yom
       Kippur was supposed to fall according to Rabbi Yoshua's way of
       counting. This again would show the existence of at least two
       conflicting calendars in those times. 
       I think BTW I read some consideration about different Calendars,
       one Solar - supported by the agricultural sedentary dwellers,
       inherited from the Cananeans/Babylonians - and a Lunar one supported
       by the ROEI ZON (sheep raisers, pastors? my English failed).
       That reference suggested even that perhaps among the followers
       of the different Calendar were the Esenians (they have very strange
       Psalms with some Heliocentric Beliefs) and from them might have
       passed on to early christians, which would explain Jesus Having
       the traditional Passover Seder - "The Last Supper" - two days
       before the real/establishment accepted/ Holyday was supposed
       to be. (According to the Evangelists he was cucified Erev Pesach
       the eve of Passover).
    
    All of this shows the possibiility of having well established Calendars
    in Antiquity, and people with a reasonable scientific approach to
    have enough data assembled as to be Checked /compensated /corrected.
    
    Hope I added some material for thought. In any case, I'd like to
    ask to those of you with easier access to an Halachic authority
    (Chaim, Fred, Cherson, Rosenbluh, etc.) if you could find some source
    for the algorithms governing our Calendar.
    
    Muchas gracias,
    Juan Carlos. 

            < All you wanted to know about....> 	
 
	   
	  Hi there! My name is Jonathan Wreschner - I'm new in Digital 
	Israel and this is my first "bite" at BAGELS.
 
	  The Jewish calendar is actually based on a lunar/solar system.
	The months are calculated by the moon, whereas the years go by 
	the sun. A month is defined as being the time between 
	successive occurrences of the moon being directly between the
	earth and the sun. 
 
	  According to tradition, the exact duration of a month is 29 
	days 12 hours and 739 "halakim" (parts of an hour which is
	divided into 1080 parts - making each "helek" or part three 
	and a third seconds). 	
               		 
	  Since the solar year is about 365 and a quarter days, we 
	have the solar year exceeding the lunar one by about 11 days.   
	Although Jewish festivals are fixed by days in months, they
	must also be in specific agricultural seasons of the year 
	which depend on the solar year. Cycles of 12 lunar months
	have to be adjusted somehow to the solar year, otherwise  
	Pesach (for example), the "Spring Festival", would slide back
	into the winter (for the Northern Hemisphere).
 	[This is in agreement with Paul's answer in .13 and takes care
	of Nitsan's question in .6.] 
 	
  	  Therefore, as Nitsan showed in an earlier note an extra month  	
	Adar II (in Hebrew Adar Sheni) was added 7 times in each cycle
	of 19 years. This cycle of 19 years is known as "mahzor katan"
	(small cycle) or "mahzor halevana" (moon cycle). The actual  
	years chosen, as mentioned by Nitsan already, (3,6,8,11,14,17,19) 
	were fixed only about 1000 years ago. In the time of the
	Bet Hamikdash (Temple), the actual years with Adar II were 
	decided upon each year depending on agricultural conditions.
	This answers Nitsan .0 and Juan Carlos .17.
 
	  Adar II is always 29 days.
 
 	  Months with 30 days are considered "maleh" (full), while
	months with 29 days are termed "haser" (deficient). The full
	months are: 	Nisan , Sivan , Av , Tishri ,Shevat and Adar I 
	(in a leap year).
	Months with 29 days are :    Iyar , Tammuz , Ellul , Tevet.
	Adar (in an ordinary year - "shana peshuta") has 29 days, as
	does Adar II in a leap year - "shana meuberet".
          	     
	  Just to make matters interesting, the months of Heshvan and  
	Kislev vary. 
	      
	  When both are 29 days the year is called deficient - "hasera".
          
	When both are 30 days the year is said to be full - "shlema",
	whilst, when Heshvan has 29 days and Kislev 30 it's an orderly
	year - "ksidra".
	Orderly - because the sequence 30 29 30 29 .... is adhered to.
 
	  [In order, the months are:  
	Nisan  Iyar  Sivan  Tammuz  Av  Ellul  Tishri  Heshvan  Kislev
	Tevet  Shevat  Adar].
	
	  Thus in an ordinary year there may be 353 , 354 or 355 days , 	
	and in a leap year there may be 383 , 384 or 385 days. 
	
	  Whew!!! That should be enough for now - more in another
	note maybe.
	
	            Jonathan Wreschner

   re .18
   
       a small typo - the duration of the month is 28 days
     12 hours and 793 "halakim" (NOT 739 as in .18).
 
       When calculated, this gives a value of 
     28 days 12 hours 44 minutes 3.333 seconds - given
     that each "helek" is 3 and a third seconds. 
 
       This figure is remarkably close to the currently
     astronomically correct figure of
     28 days 12 hours 44 minutes 2.841 seconds.
 
       Not bad - when one considers that Rabban Gamliel of Yavne,
     who lived after the destruction of the Second Temple, 
     gives the figure in the Talmud Bavli tractate Rosh Hashana 25a.

       Incidentally, the same page has the story quoted by 
     Juan Carlos in .17 about Rabban Gamliel and Rabbi Yehoshua.
 
     Jonathan Wreschner

Here's a dumb question and a request for a reference:

1.  My secular calendars (2 of them) show a new moon on Jan. 11, 1994.  
Rosh Chodesh occurs today, Jan. 13.  I could get a one-day difference, 
due to an early molad and a late "official" secular determination, but 
this looks too far apart to me.  What's the explanation, please?

2.  Can anyone refer me to a book that describes the workings of the 
calendar?  The previous two replies are most helpful, but I would like 
to read a bit more.  The one book I found had a chapter on "Astromony" 
[sic], so I was a bit leery of it.

- Scott

I took a look in the big dictionary here in the office and found two meanings
for "new moon". Definition 1 refers to that phase of the moon where the dark
side is towards the Earth. Definition 2 refers to the time when the moon can
first been seen (and mentions Rosh Chodesh).

There seems to be enough ambiguity in the definition of the term to allow
a 2-day difference.

Dave

re 197.20

>2.  Can anyone refer me to a book that describes the workings of the 
>calendar?  The previous two replies are most helpful, but I would like 
>to read a bit more.  

Hello Scott,

Sorry for the delay in replying to you.

You should be able to get a lot of useful information from the Encyclopedia
Judaica which should be available in any good library, under the entry 
"Calendar".  At the end of the article there will be references for books on
the topic.

Also note #75 in BAGELS occasionally has something on the calendar.  Just today
I saw 75.1138 which quotes a book on the subject.  
Do a SEARCH CALENDAR/NOTE=75.* and see what comes up.

Regards,

Jonathan

Hi,

A new question for an "old" subject:

What happens to celebrations [such as yhertziets (sp), etc.] which originally 
occurred on a date (such as during ADAR II), when that date does not exist 
during the current year?   Would days that would fall during ADAR II be 
celebrated on the first of the following month (Nisan) for the years that ADAR 
II does not exist?  If this is the case, then I assume the same would hold true 
for the "missing days" of Heshvan, Kislev, as well.


Thanks for any information,

ed

>Hi,
>
>A new question for an "old" subject:
>
>What happens to celebrations [such as yhertziets (sp), etc.] which originally 
>occurred on a date (such as during ADAR II), when that date does not exist 
>during the current year?   Would days that would fall during ADAR II be 
>celebrated on the first of the following month (Nisan) for the years that ADAR 
>II does not exist?  If this is the case, then I assume the same would hold true 
>for the "missing days" of Heshvan, Kislev, as well.
>
>
>Thanks for any information,
>
>ed

With regard to dates in Adar II, it is considered the same as Stam/Regular Adar.
Dates in Adar I are moved into Adar. With regard to the other "missing" dates, I
don't know. 

	Yaacov