Rabbi Shimshon Refael Hirsch has a number of interesting writeups on the relationships between words and their meaning. This shabbos, our rabbi brought up the relationship between מלאך (Malach - Angel or messenger) and מלאכה (Melacha - work). This is the way that Hebrew connects words to the noun that applies to them. Consider the piyut on יום כפור, that starts הנה כחומר, as an example of seeing how the noun is created from the מפעיל, the causative usage.
In Parshas Vayera, the meforshim say that the reason that three מלאכים came to אברהם and only two continued on to סדום to save לוט was that a מלאך only exists for as long as its task (מלאכה) has not yet been accomplished. Once the job is done, the מלאך no longer exists. Similarly, we can connect the 39 מלאכות of שבת to the person doing them and to the definition as those things being done for the משכן. Similarly, the word מלאכה is used when speaking of the "work" that השם "did" creating the world. We see that this term is used for a task that is directly connected to the person doing the job.
This is opposed to the word עבודה which seems to be used for work that is imposed from without and is meant as "service". For example, a person who does עבודה is an עבד which is normally translated as "slave" or "servant". This means that instead of being something that is intrinsic to the being (מלאכה performed by a מלאך), this עבודה is an external task that is assigned by a "master". The being performing the עבודה is totally separate from the "work" being done. As a result, a מלאך cannot do עבודה as its "work" is intrinsic to its being. This means that animals, lacking free will, and created to work only according to the natural laws set up by השם can only do עבודה. A human being, created by השם, with both aspects of the universe, and with the free will to choose between them, can perform מלאכת or עבודה, . An example is seen in Parshas Bereishis (פרק 2: פסוק 15) where the purpose of אדם being in גן עדן is "לעבדה ולשמרה".
Sunday, October 31, 2010
Wednesday, October 20, 2010
Avrohom in Geror
A post on mail Jewish asked
Even those who fault Avraham for going to Mitzrayim, do not fault him for going to Grar. Yitzchak was forbidden to leave Eretz Canaan as a result of the Akeidah, but Hashem told him (in Toldos) specifically to stay in Grar. Thus, Grar was not outside of Canaan and there was nothing wrong with that. The only problem was the trick that Avrohom used. As Avraham tells Avimelech, this trick was actually necessary and part of their normal behavior. It is only brought up in the Torah when the king (who was the only one who could get away with violating Avraham's rights as the "brother" of an unmarried woman) actually took the "sister" in order to make her part of her harem.
Rav S. R. Hirsch (among others) points out that this trick was designed to save the two of them from the general population of the city state. As Rav Hirsch says,(as translated in the Judaica Press edition) in Vayera chapter 20 pasuk 2.
In Parshat Lech-Lecha, we read about the incident where Avram and Sarai are driven from Cana'an because of a famine and go to live in Egypt. In order to protect Avram's life, they declare themselves as brother and sister.There are are several different questions being asked that need to be dealt with.
Several of the commentators, especially the Ramban, state that Avram erred in this matter because he left Cana'an without G-d's command, and thereby risked Sarai's life and honor. (The Ramban also sees the Egyptian exile of Avraham's descendents as a punishment for this sin.)
But what about the additional sin of putting Sarai (a married women) in a position where she might have martyred herself and not submit to gilui arayot (a severe illicit relationship). Here, we can probably say that before receiving the Torah, the rule that requires martyrdom instead of gilui arayot does not apply.
Now we move to Parshat Vayera, and this time we read of a more puzzling incident where Avraham and Sara go to live in Grar, and again adopt the "brother and sister" story. But this time, there was no famine that drove them away from Eilonai-Mamrei! (Rashi says that one of the reasons for the move was to distant themselves from Lot, who became infamous because of his relationships with his daughters.) Of course, Sara was taken to King Avimelech's house. Sara was ultimately saved from being violated only because of G-d's intervention.
Since there was no famine in Cana'an, what was Avraham's justification for moving to Grar, and then using the "brother and sister" story again? (This was against Sara's will, according to Rashi.) The dangers were very real and no justification is stated in the Torah. In fact, during G-d's dealings with Avimelech, Avimelech is shown to be a tzadik and Avraham is not shown in that light.
Later, during the confrontation between Avraham and Avimelech, Avraham excuses his behavior by saying "I thought there was no fear of G-d in this place, and I expected to be killed because of my wife". So why did he come to Grar?
So how do we explain Avraham's behavior in this incident?
Even those who fault Avraham for going to Mitzrayim, do not fault him for going to Grar. Yitzchak was forbidden to leave Eretz Canaan as a result of the Akeidah, but Hashem told him (in Toldos) specifically to stay in Grar. Thus, Grar was not outside of Canaan and there was nothing wrong with that. The only problem was the trick that Avrohom used. As Avraham tells Avimelech, this trick was actually necessary and part of their normal behavior. It is only brought up in the Torah when the king (who was the only one who could get away with violating Avraham's rights as the "brother" of an unmarried woman) actually took the "sister" in order to make her part of her harem.
Rav S. R. Hirsch (among others) points out that this trick was designed to save the two of them from the general population of the city state. As Rav Hirsch says,(as translated in the Judaica Press edition) in Vayera chapter 20 pasuk 2.
"... unmarried virgins must have been much safer amongst the people than married women. It seems to have been only princes that unmarried strangers had reason to fear. And actually it was again only a king that dared to take her, and who later on has no scruples in admitting it."Avimelech, in fact, is wrong even though he *thinks* that he is innocent. When Hashem "speaks" to him, Avimelech says
בתם לבבי ובנקיון כפי עשיתי
in the innocence of my heart and the integrity of my hands I did thisHowever, when Hashem responds, he says
גם אני ידעתי כי בתם לבבך עשית זאת
I know that you thought that you were acting innocently (my translation)We see that Hashem acknowledges that Avimelech thought that he was right, but tells him that not only was he wrong, but he needs to get Avrohom to pray for him or he would die as a result of what he did
ויתפלל בעדך וחיה And he will pray for you and you will liveThus we see that Avimelech was deserving of death for the abuse of power. Note that Avimelech does not dispute the fact that Avrohom used the trick on everyone else. He is just upset that Avrohom did not let him know what was going on. Indeed, Avimelech in Toldos tells Yitzchak
כמעט שכב אחד העם את אשתך
One of the people might have "taken" your wife (in "nicer" language)Rashi points out that this means he himself might have taken her. In fact, Avimelech there has to explicitly warn the people not to "touch" either Yitzchak or Rivkah, even though Eisav was already grown (and according to some meforshim) running the family "defense forces". Avimelech in Vayera did not dare let Avraham stay in the city itself. He couched his "request" that Avraham leave in nicer language by telling him that he was free to settle wherever in the land under his (Avimelech's) control that he wanted to.
Sunday, October 17, 2010
Difference between תולדות אדם and תולדות שם
The list of generations in פרק ה בראשית for תולדות אדם and the list of generations in פרק יא נח for תולדות שם is that there is an extra פסוק in בראשית. The standard in בראשית is as follows:
The obvious difference between the two may be the fact that the ten generations until נח ends with the destruction of the world in the מבול. The ten generations from נח to אברהם ends with the reestablishment of belief in Hashem and the beginning of what will become the Jewish people.
This is discussed in a number of places. Rabbi Munk references רבינו בחיי. It is also discussed in ספורנו and כלי יקר and אור החיים as well as Rabbi Zalman Sorotzkin's אזנים לתורה (Insights in the Torah). The difference is connected to the the fact that the ten generations from אדם to נח lead to the end of the world and the מבול. On the other hand, the ten generations from נח to אברהם leads to the birth of אברהם אבינו. Rabbi Munk points out that this is the beginning of the development of the world that will end with the coming of the משיח.
Rabbi Sorotzkin says that the extra פסוק is to point out that this is actually a praise of the people who are listed as it emphasizes that they died natural deaths and were not punished by being killed in the flood. This is similar to the explanation given when בנות צלפחד explain that their father "died in the desert" in order to show that he was not part of those who died because of the rebellion of Korach or one of the other explicit punishments for the various sins. As רבינו נחיי says, there is no need for the third pasuk since the flood was over and we would no longer need to emphasize the fact of "natural" death.
An alternate answer given by Rabbi Sorotzkin (and others) compares the deaths in the מבול to the death of יואב. The גמרא states the the extra phrase "he died" means that he did not leave any children. The מבול can be considered the complete destruction of the world, and נח, far from being an "heir" of his ancestors. can be considered a "new creation". Thus, everything that happened before has been wiped out and is "dead".
The first death explicitly given in the genealogical table between נח and אברהם was פלג (Peleg) who died in 1996, the year of the dispersion. At that time אברהם was 48 years old. Thus all of his ancestors were alive, not only at his birth, but for the significant occurrence that ended that stage of existence. The Medrash says that Avrohom's brother הרן was the first person to die while his father was still alive, and by implication, he would have been the first person to die since the flood. As a result, the medrash of the כבשן האש had to have occurred while נמרוד still controlled the "civilized" world before the dispersion. This means the the actual major event of the age, the refusal of אברהם to succumb to the idolatry of his age and the initial revolt that led to מתן תורה and will lead to ימות המשיח, occurred while every link in the generational chain was still alive.
The final end of the generations also shows the difference between נח and אברהם. אברהם tried his best to save the world, and whether he succeeded or not, as with his brother or with סדום, the attempt still allowed the world to continue and led to life. The names show the difference between them. נח basically sat back, did what Hashem told him and left it at that. While he was saved, the entire world died and it was as if he was a new creation starting from scratch. אברהם worked and strove and not only became the "father" of the future, but was able to keep his ancestors alive as well.
- X lived for m years and fathered Y
- X lived n years after fathering Y and fathered sons and daughters.
- All the years of X's life were m+n years, and he died.
The obvious difference between the two may be the fact that the ten generations until נח ends with the destruction of the world in the מבול. The ten generations from נח to אברהם ends with the reestablishment of belief in Hashem and the beginning of what will become the Jewish people.
This is discussed in a number of places. Rabbi Munk references רבינו בחיי. It is also discussed in ספורנו and כלי יקר and אור החיים as well as Rabbi Zalman Sorotzkin's אזנים לתורה (Insights in the Torah). The difference is connected to the the fact that the ten generations from אדם to נח lead to the end of the world and the מבול. On the other hand, the ten generations from נח to אברהם leads to the birth of אברהם אבינו. Rabbi Munk points out that this is the beginning of the development of the world that will end with the coming of the משיח.
Rabbi Sorotzkin says that the extra פסוק is to point out that this is actually a praise of the people who are listed as it emphasizes that they died natural deaths and were not punished by being killed in the flood. This is similar to the explanation given when בנות צלפחד explain that their father "died in the desert" in order to show that he was not part of those who died because of the rebellion of Korach or one of the other explicit punishments for the various sins. As רבינו נחיי says, there is no need for the third pasuk since the flood was over and we would no longer need to emphasize the fact of "natural" death.
An alternate answer given by Rabbi Sorotzkin (and others) compares the deaths in the מבול to the death of יואב. The גמרא states the the extra phrase "he died" means that he did not leave any children. The מבול can be considered the complete destruction of the world, and נח, far from being an "heir" of his ancestors. can be considered a "new creation". Thus, everything that happened before has been wiped out and is "dead".
The first death explicitly given in the genealogical table between נח and אברהם was פלג (Peleg) who died in 1996, the year of the dispersion. At that time אברהם was 48 years old. Thus all of his ancestors were alive, not only at his birth, but for the significant occurrence that ended that stage of existence. The Medrash says that Avrohom's brother הרן was the first person to die while his father was still alive, and by implication, he would have been the first person to die since the flood. As a result, the medrash of the כבשן האש had to have occurred while נמרוד still controlled the "civilized" world before the dispersion. This means the the actual major event of the age, the refusal of אברהם to succumb to the idolatry of his age and the initial revolt that led to מתן תורה and will lead to ימות המשיח, occurred while every link in the generational chain was still alive.
The final end of the generations also shows the difference between נח and אברהם. אברהם tried his best to save the world, and whether he succeeded or not, as with his brother or with סדום, the attempt still allowed the world to continue and led to life. The names show the difference between them. נח basically sat back, did what Hashem told him and left it at that. While he was saved, the entire world died and it was as if he was a new creation starting from scratch. אברהם worked and strove and not only became the "father" of the future, but was able to keep his ancestors alive as well.
Sunday, September 26, 2010
How the calendar might look with a Sanhedrin
It is an interesting exercise to attempt to compare what the Sanhedrin might announce to the calculated calendar that we use
While the molad is announced in terms of Jerusalem Solar Time, the tables below are shown in terms of Israeli clock time, based of the time zone (UTC +2). This allows the announced molad to be compared to the actual astronomical conjunction. The announced molad is based on the average calculated lunar cycle.
For the actual conjunction, sunset, and moonset times, I used the time charts at Time and Date along with a guess at visibility based on .6 of the time between sunset and moonset.
I assumed the Sanhedrin magically came into existence in time to declare Cheshvan because I did not want to deal with Rosh Hashannah of this year.
I also took the calculated Molad (Solar Time in Yerushalayim) and converted it to the Israeli Time Zone (UTC + 2) Clock Time as explained by Torah Tidbits in Yerushalayim. For example, the 5770 table gives the time as the Rambam declares it, as we currently announce it, and accordint to Israeli Clock Time. Thus, the time being shown is clock time rather than the actual announced time. This difference is based on the fact that noon in Solar Time (as used in the announced molad) is approximately 11:40 AM by the clock.
The point is to show what the effects would be with the various possibilities as the year progresses. I left out Rosh Hashanna because it seems that when you get a "two day" situation, Rosh Hashanna becomes Tishrei 1 and 2 rather than Elul 30 and Tishrei 1. The reason being that the entire idea of two days is based on the waiting for the declaration and the way korbanos are handled. Since Rosh Hashanna starts as soon as the declaration is made and everywhere in the country treats it as two days mishum safek, it is possible that the way we handle the same situation with every other month would be different. In any case, the entire set of comments was to show how the differences would propagate through the year.
Calculated Molad chart for the year 5770
This table shows the actual (astronomical) time of the new moon (conjunction) in Israel Time. This can be gotten from a number of tables, such as the Naval Observatory time showed in the previous posting.
Astronomical Conjunction chart for 5770
Calculated Average Molad chart for the year 5771
Note that the first visibility range is delayed because the first date is October 8, 5:16 PM – 5:26 PM. This is probably too short a time to actually see the moon. The following month, the first moonrise is at 4:45 PM which is less than ten hours. If the moon is seen on or before day 29 of the month, then the Sanhedrin would be able to declare the next day Rosh Chodesh and the previous month would be a 29 day month. Otherwise, the previous day would be a two day Rosh Chodesh by default. This occurs for Chesvan and Kislev. Note that Teves has two possibilities. If witnesses see the moon at the first available date (Dec 6), then Dec 7 would be the only day of Rosh Chodesh, unlike the calculated calendar which has two days. This would make the fast of Asara B'Teves occur one day earlier, Thursday, December 16, instead of Friday, December 17. This would also affect the declaration of the month of Shvat. Since it is the middle of the rainy season, it is very probable that the witnesses would miss the first sighting of the moon, forcing Teves to have tw days of Rosh Chodesh, just like the calculated calendar.
If Teves only had one day of Rosh Chodesh (December 7), then January 5 would be day number 30 of that month. This would force Shvat to have a two day Rosh Chodesh and would bring it back in sync with the calculated calendar.
Adar II now has two possibilities again because of the end of the rainy season. It is also possible that it would be missed because of the early time within the rang that the visibility occurs (19 hours 18 minutes). If it were visible, the Sanhedrin might deliberately not hold court because it would force Purim to occur on Shabbos. This affects Nisan, just as Teves did Shvat.
Note that Daylight Savings Time in Israel starts April 2. Thus, All time from April on are in Daylight Savings Time.
Nisan now has three possibilities because of the tw possibilities of Adar II. If Adar II had only one day Rosh Chodesh, then Nisan is forced to have two days Rosh Chodesh and comes back into sync with the calculated calendar. This is the same situation as if Adar II had two days Rosh Chodesh and the witnesses saw the moon in time for Nisan to have one day Rosh Chodesh. It is probable that they would see it as the moon would be 26 hours old. If they do not see it, Nisan has two days Rosh Chodesh and Pesach becomes Wednesday April 20 instead of Tuesday April 19. This is a significant effect and shows why we need the calendar to be precise. This also shows the reason for two days of Yom Tov in Chutz La'Aretz.
Iyar can now be either a one day or two day Rosh Chodesh depending on what had happened with Nisan (assuming that the witnesses do see the moon at the designated time. If they miss the moon, it would of course be forced to be a two day Rosh Chodesh.
Because Shavuos is defined as being counted from Pesach, the date would have been defined by what happened to Nisan.
Had Iyar had a single day of Rosh Chodesh, June 2 would have been the thirtieth day of the month forcing two days of Rosh Chodesh whether the moon was seen or not. If there had been two days of Rosh Chodesh, it would have again depended on whether or not the moon had been seen. This would set up three possibilities.
This sets up three possibilities for Sivan, but the first of Sivan woul occur on either June 3 or 4. This leads to Tamuz having one or two days Rosh Chodesh, but in either case, the first of the month is July 3. This brings it back in sync with the calculated calendar.
Av can now have one or two days Rosh Chodesh, meaning that Tisha B'Av can be on August 9 or 10.
While the moon on the day of the conjunction of Elul (Aug 29) may be visible, the time interval is only two minutes so it would probably be too close to the sun. If we assume that the second interval is seen, then the first of Elul is on the same day in either case. This allows Rosh Hashana to start as expected by the calculated calendar. On the other hand, if that day is not seen, Elul starts even later and causes a problem with Rosh Hashana because Elul 29 is pushed forward to September 29.
The Conjunction for Rosh Hashana 5772 is September 27 at 2:09 Am, with a possible visibility at 6:45 PM on September 28 (40 h 36 m moon age). This is Elul 29 according to the analysis above, which would make Rosh Hashanna occur on September 29 and 30. This is the same as determined by the calculated calendar.
Conjunction chart for the year 5771
While the molad is announced in terms of Jerusalem Solar Time, the tables below are shown in terms of Israeli clock time, based of the time zone (UTC +2). This allows the announced molad to be compared to the actual astronomical conjunction. The announced molad is based on the average calculated lunar cycle.
For the actual conjunction, sunset, and moonset times, I used the time charts at Time and Date along with a guess at visibility based on .6 of the time between sunset and moonset.
I assumed the Sanhedrin magically came into existence in time to declare Cheshvan because I did not want to deal with Rosh Hashannah of this year.
I also took the calculated Molad (Solar Time in Yerushalayim) and converted it to the Israeli Time Zone (UTC + 2) Clock Time as explained by Torah Tidbits in Yerushalayim. For example, the 5770 table gives the time as the Rambam declares it, as we currently announce it, and accordint to Israeli Clock Time. Thus, the time being shown is clock time rather than the actual announced time. This difference is based on the fact that noon in Solar Time (as used in the announced molad) is approximately 11:40 AM by the clock.
The point is to show what the effects would be with the various possibilities as the year progresses. I left out Rosh Hashanna because it seems that when you get a "two day" situation, Rosh Hashanna becomes Tishrei 1 and 2 rather than Elul 30 and Tishrei 1. The reason being that the entire idea of two days is based on the waiting for the declaration and the way korbanos are handled. Since Rosh Hashanna starts as soon as the declaration is made and everywhere in the country treats it as two days mishum safek, it is possible that the way we handle the same situation with every other month would be different. In any case, the entire set of comments was to show how the differences would propagate through the year.
Calculated Molad chart for the year 5770
| Month | Date | Israel Time | Rosh Chodesh |
| Cheshvan | Sunday, October 18, 2009 | 11:10 PM IST | Sun/Mon Oct 18/19 |
Kislev | Tuesday, November 17, 2009 | 11:54 AM IST | Tue/Wed Nov 17/18 |
Teves | Thursday, December 17, 2009 | 12:39 AM IST | Fri, Dec 18 |
Shvat | Friday, January 15, 2010 | 1:23 PM IST | Sha Jan 16 |
Adar | Sunday, February 14, 2010 | 2:07 PM IST | Sun/Mon Feb 14/15 |
Nisan | Monday, March 15, 2010 | 2:51 PM IST | Tue, Mar 16 |
Iyar | Wednesday, April 14, 2010 | 4:35 AM IDT | Wed/Thu Apr 14/15 |
Sivan | Thursday, May 13, 2010 | 5:19 PM IDT | Fri May 14, 2010 |
Tamuz | Saturday, June 12, 2010 | 6:03 AM IDT | Sha/Sun Jun 12/13 |
Av | Sunday, July 11, 2010 | 6:47 PM IDT | Mon, Jul 12 |
Elul | Tuesday, August 10, 2010 | 7:31 AM IDT | Tue/Wed Aug 10/11 |
This table shows the actual (astronomical) time of the new moon (conjunction) in Israel Time. This can be gotten from a number of tables, such as the Naval Observatory time showed in the previous posting.
Astronomical Conjunction chart for 5770
Month | Date | Israel Time |
Cheshvan | Sunday, October 18, 2009 | 7:33 AM IST |
Kislev | Monday, November 16, 2009 | 9:14 PM IST |
Teves | Wed, December 16, 2009 | 12:39 AM IST |
Shvat | Friday, January 15, 2010 | 1:23 PM IST |
Adar | Sunday, February 14, 2010 | 2:07 PM IST |
Nisan | Monday, March 15, 2010 | 2:51 PM IST |
Iyar | Wednesday, April 14, 2010 | 4:35 AM IDT |
Sivan | Friday, May 14, 2010 | 5:19 PM IDT |
Tamuz | Saturday, June 12, 2010 | 6:03 AM IDT |
Av | Sunday, July 11, 2010 | 6:47 PM IDT |
Elul | Tuesday, August 10, 2010 | 7:31 AM IDT |
Calculated Average Molad chart for the year 5771
| Month | Day | Molad | Israel Clock Time | Rosh Chodesh |
Cheshvan | 30 Tishri 5771 Fri 8 Oct 2010 | 08:20:02 AM | 7:59 AM IST | Fri/Sha Oct 8/9 |
Kislev | 30 Cheshvan 5771 Sat 6 Nov 2010 | 09:04:03 PM | 8:43 PM IST | Sun/Mon Nov 7/8 |
Teves | 29 Kislev 5771 Mon 6 Dec 2010 | 09:48:04 AM | 9:27 AM IST | Tue/Wed Dec 7/8 |
Shvat | 29 Teves 5771 Tue 4 Jan 2011 | 10:32:05 PM | 10:11 PM IST | Thu Jan 6 |
Adar I | 29 Shevat 5771 Thu Feb 3 2011 | 11:16:06 AM | 10:55 AM IST | Fri/Sha Feb 4/5 |
Adar II | 28 Adar A 5771 Fri March 4 2011 | 12:00:07 AM | 11:39 PM IST | Sun/Mon Mar 6/7 |
Nisan | 28 Adar B 5771 Sun April 3 2011 | 12:44:08 PM | 1:23 AM IDT | Tue Apr 5 |
Iyar | 29 Nisan 5771 Mon May 3 2011 | 01:28:09 AM | 2:08 AM IDT | Wed/Thu May 4/5 |
Sivan | 28 Iyar 5771 Wed June 1 2011 | 02:12:10 PM | 2:52 PM IDT | Fri June 3 |
Tamuz | 29 Sivan 5771 Fri July 1 2011 | 02:56:11 AM | 3:36 AM IDT | Sha/Sun July 2/3 |
Av | 28 Tamuz 5771 Sat July 30 2011 | 03:40:12 PM | 4:20 PM IDT | Mon Aug 1 |
Elul | 29 Av 5771 Mon Aug 29 2011 | 04:24:13 AM | 5:04 AM IDT | Tue/Wed Aug 30/31 |
Dr. Roy Hoffman of the Israel new Moon Society has said that
The best time to see the crescent Moon, according to my research ("Observing the new Moon" R. E. Hoffman, Monthly Notes Roy. Astron. Soc., 340, 1039-1051 (2003).), is 0.6 of the time between Sunset and Moonset. The first crescent Moon appears between 15 and 55 hours after the true conjunction.
He has published predictions of possible first sightings of the new moon at
You can download my predictions for the next year at http://chem.ch.huji.ac.il/nmr/foo/handouts/5771e.pdf, and for last year at http://chem.ch.huji.ac.il/nmr/foo/handouts/5770e.pdfSome of these estimates show that the moon would definitely not be visible to the naked eye at that time.
I should point that that as Dr. Hoffman says
I do not publish calendars based on sightings because we are commanded to use our calculated calendar until a recognized Sanhedrin rules otherwise. If you do publish such a calendar, it is more than likely that a few individuals will follow it in contradiction to the halakhah.
Rosh Hashanna of 5772 will be Thu/Fri Sept 29/30
The actual conjunction and the possible “first visibility” list is shown below.
Note that the first visibility range is delayed because the first date is October 8, 5:16 PM – 5:26 PM. This is probably too short a time to actually see the moon. The following month, the first moonrise is at 4:45 PM which is less than ten hours. If the moon is seen on or before day 29 of the month, then the Sanhedrin would be able to declare the next day Rosh Chodesh and the previous month would be a 29 day month. Otherwise, the previous day would be a two day Rosh Chodesh by default. This occurs for Chesvan and Kislev. Note that Teves has two possibilities. If witnesses see the moon at the first available date (Dec 6), then Dec 7 would be the only day of Rosh Chodesh, unlike the calculated calendar which has two days. This would make the fast of Asara B'Teves occur one day earlier, Thursday, December 16, instead of Friday, December 17. This would also affect the declaration of the month of Shvat. Since it is the middle of the rainy season, it is very probable that the witnesses would miss the first sighting of the moon, forcing Teves to have tw days of Rosh Chodesh, just like the calculated calendar.
If Teves only had one day of Rosh Chodesh (December 7), then January 5 would be day number 30 of that month. This would force Shvat to have a two day Rosh Chodesh and would bring it back in sync with the calculated calendar.
Adar II now has two possibilities again because of the end of the rainy season. It is also possible that it would be missed because of the early time within the rang that the visibility occurs (19 hours 18 minutes). If it were visible, the Sanhedrin might deliberately not hold court because it would force Purim to occur on Shabbos. This affects Nisan, just as Teves did Shvat.
Note that Daylight Savings Time in Israel starts April 2. Thus, All time from April on are in Daylight Savings Time.
Nisan now has three possibilities because of the tw possibilities of Adar II. If Adar II had only one day Rosh Chodesh, then Nisan is forced to have two days Rosh Chodesh and comes back into sync with the calculated calendar. This is the same situation as if Adar II had two days Rosh Chodesh and the witnesses saw the moon in time for Nisan to have one day Rosh Chodesh. It is probable that they would see it as the moon would be 26 hours old. If they do not see it, Nisan has two days Rosh Chodesh and Pesach becomes Wednesday April 20 instead of Tuesday April 19. This is a significant effect and shows why we need the calendar to be precise. This also shows the reason for two days of Yom Tov in Chutz La'Aretz.
Iyar can now be either a one day or two day Rosh Chodesh depending on what had happened with Nisan (assuming that the witnesses do see the moon at the designated time. If they miss the moon, it would of course be forced to be a two day Rosh Chodesh.
Because Shavuos is defined as being counted from Pesach, the date would have been defined by what happened to Nisan.
Had Iyar had a single day of Rosh Chodesh, June 2 would have been the thirtieth day of the month forcing two days of Rosh Chodesh whether the moon was seen or not. If there had been two days of Rosh Chodesh, it would have again depended on whether or not the moon had been seen. This would set up three possibilities.
This sets up three possibilities for Sivan, but the first of Sivan woul occur on either June 3 or 4. This leads to Tamuz having one or two days Rosh Chodesh, but in either case, the first of the month is July 3. This brings it back in sync with the calculated calendar.
Av can now have one or two days Rosh Chodesh, meaning that Tisha B'Av can be on August 9 or 10.
While the moon on the day of the conjunction of Elul (Aug 29) may be visible, the time interval is only two minutes so it would probably be too close to the sun. If we assume that the second interval is seen, then the first of Elul is on the same day in either case. This allows Rosh Hashana to start as expected by the calculated calendar. On the other hand, if that day is not seen, Elul starts even later and causes a problem with Rosh Hashana because Elul 29 is pushed forward to September 29.
The Conjunction for Rosh Hashana 5772 is September 27 at 2:09 Am, with a possible visibility at 6:45 PM on September 28 (40 h 36 m moon age). This is Elul 29 according to the analysis above, which would make Rosh Hashanna occur on September 29 and 30. This is the same as determined by the calculated calendar.
| Month | Conjunction | Visibility Range | “best Time” (.6 of way) | Rosh Chodesh |
Cheshvan | Thu, Oct 7, 2010 8:44 PM IST | Oct 9 5:14 – 6:10 PM | 5:47 PM 45 h 3 m | Fri/Sha Oct 8/9 |
Kislev | Sat, Nov 6, 2010 6:52 AM IST | Nov 7 4:45 – 5:36 PM | 5:15 PM 34 h 23 m | Sun/Mon Nov 7/8 |
Teves | Sun, Dec 5, 2010 7:36 PM IST | Dec 6 4:35 – 5:14 PM | 4:58 PM 21 h 22 m | Tue Dec 7 |
Teves | Sun, Dec 5, 2010 7:36 PM IST | Dec 7 4:35 – 6:16 PM | 5:35 PM 46 h 50 m | Tue/Wed Dec 7/8 |
Shvat | Tue, Jan 4, 2011 11:03 AM IST | Jan 4 4:48 – 5:00 PM | 4:55 PM 5 h 52 m | Too early to see |
Shvat | Tue, Jan 4, 2011 11:03 AM IST | Jan 5 4:49 – 5:59 PM | 5:31 PM 30 h 28 m | Wed/Thu Jan 5/6 |
Shvat | Tue, Jan 4, 2011 11:03 AM IST | Jan 5 4:49 – 5:59 PM | 5:31 PM 30 h 28 m | Thu Jan 6 |
Adar I | Thu, Feb 3, 2011 4:31 AM IST | Feb 3 5:15 – 5:45 PM | 5:33 PM 13 h 2 m | Too early to see |
Adar I | Thu, Feb 3, 2011 4:31 AM IST | Feb 4 5:16 – 6:39 PM | 6:15 PM 13 h 44 m | Fri/Sha Feb 4/5 |
Adar II | Fri, Mar 4, 2011 10:46 PM IST | Mar 5 5:40 – 6:20 PM | 6:04 19 h 18 m | Sun Mar 6 |
Adar II | Fri, Mar 4, 2011 10:46 PM IST | Mar 6 5:40 – 7:13 | 6:35 PM 43 h 49 m | Sun/Mon Mar 6/7 |
Nisan | Sun, Apr 3, 2011 5:32 PM IDT | April 4 7:00 – 7:57 PM | 7:34 PM 26 h 2 m | Mon/Tue Apr 4/5 |
Nisan | Sun, Apr 3, 2011 5:32 PM IDT | April 4 7:00 – 7:57 PM | 7:34 PM 26 h 2 m | Tue Apr 5 |
Nisan | Sun, Apr 3, 2011 5:32 PM IDT | April 5 7:01 – 8:52 PM | 7:37 PM 50 hours 5 m | Tue/Wed Apr 5/6 |
Iyar | Tue, May 3, 2011 9:51 AM IDT | May 3 7:20 – 7:42 PM | 7:33 PM 9 h 42 m | Too early to see |
Iyar | Tue, May 3, 2011 9:51 AM IDT | May 4 7:21 – 8:39 | 8:07 PM 34 h 16 m | Wed/Thu May 4/5 |
Iyar | Tue, May 3, 2011 9:51 AM IDT | May 4 7:21 – 8:39 | 8:07 PM 34 h 16 m | Wed May 4 |
Sivan | Thu, Jun 2, 2011 12:03 AM IDT | Jun 2 7:40 – 8:21 PM | 8:04 PM 20 h 1 m | Thu/Fri June 2/3 |
Sivan | Thu, Jun 2, 2011 12:03 AM IDT | Jun 2 7:40 – 8:21 PM | 8:04 PM 20 h 1 m | Fri June 3 |
Sivan | Thu, Jun 2, 2011 12:03 AM IDT | Jun 3 7:40 – 9:12 PM | 8:35 PM 44 h 32 m | Fri/Sha June 3/4 |
Tamuz | Fri, Jul 1, 2011 11:54 AM IDT | July 2 7:49 – 8:39 | 8:19 PM 32 h 25 m | Sha/Sun July 2/3 |
Tamuz | Fri, Jul 1, 2011 11:54 AM IDT | July 2 7:49 – 8:39 | 8:19 PM 32 h 25 m | Sun July 3 |
Av | Sat, Jul 30, 2011 9:40 PM IDT | July 31 7:37 – 7:55 PM | 7:47 PM 22h 7 m | Mon Aug 1 |
Av | Sat, Jul 30, 2011 9:40 PM IDT | Aug 1 7:36 – 8:32 PM | 8:09 PM 46 h 29 m | Mon/Tue Aug 1/2 |
Elul | Mon, Aug 29, 2011 6:04 AM | Aug 30 7:06 – 7:42 | 7:27 PM 37 h 23 m | Tue/Wed Aug 30/31 |
Elul | Mon, Aug 29, 2011 6:04 AM | Aug 30 7:06 – 7:42 | 7:27 PM 37 h 23 m | Wed Aug 31 |
Thursday, September 16, 2010
How a Sanhedrin might not change the printed calendar this year
The time and date calendar can be used to estimate if the eidim can see the moon after the astronomical molad and allow us to guess if the Sanhedrin would declare the new month on the same or a different day than calculated by our fixed calendar.
For example, the astronomical molad for Cheshvan is 8:44 PM October 7. The moon times for October 8 are 6:12 AM rising and 5:26 PM setting. The noon % illumination is .8% at 11:52. The sunrise and sunset times are 5:37 and 5:16. Thus, it would probably not be visible at moonrise. The noon illumination on October 9 is 4.1 % at 12:49. I would therefore guess that the visibility during this time would be about 1%. This may be visible during the ten minutes after sunset and before moonset (about 17 hours after the astronomical molad). This would mean that Beis Din could not declare the chodesh until October 9 (since they must do so during the day). This would mean that the declared month would match the calculated month and Tishrei would have 30 days as the printed calendars show.
Kislev has the astronomical new moon at 6:52 AM on November 6, which seems to imply that eidus between moonset and sunset on November 6 might be possible however moonset and sunset are both 4:45 PM so it would probably be drowned out. If it was visible, Cheshavan would be a 29 day month, while if not (as is most probable) it would be a 30 day month as shown in the printed calendar
This seems to show that for at least Cheshvan and Kislev, the Sanhedrin would most probably declare the chodesh to be the same as our calculated calendar. It might be interesting to estimate what might happen during the rest of the months of the year and see what would have to be done to ensure that next Rosh Hashannah did not come out on one of the "forbidden" dates.
There are sites that calculate the percent visibility of the moon for a specific date and time. For example, the U.S. Naval observatory says
I would guess that they must have had some occurrance that managed to make it within 15.5 hours (in perfect conditions) in order to set the record. I saw that they did not say when the record was set. Phil Chernofsky has told me that the Israel New Moon Society uses a figure of 18 - 20 hours after the conjuction (astronomical molad) for the earliest possible visibility. I think that if we use the 18 hour figure to get the % of illumination we could calculate. Given that 29.5 days is 708 hours, 18 - 20 hours is approximately 5% - 6% illuminated. We can then use the illumination table to estimate if the moon would be seen around moonset on a particular day. This assumes that the eidim would see the moon between sunset and moonset only. Thus, I would add 18 hours to the conjunction and go to the next sunset time for that estimate.
The Naval observatory calculator generates a table for the year showing the percent illuminated for each day at midnight or noon in Universal Time or one of the U.S. timezones. This would be 7 hours earlier than the time shown for Yerushalayim. The South African Astronomical Observatory has a table of predictions showing where the moon would be visible as well as when it is first visible in South Africa. Another calculator is found at the fishing site http://www.noreast.com/moon/ This calculates the % illuminates at a set hour for a given day. It appears that this is also Eastern Time. Because the Muslims still use "eidus" as the start of their months, they have developed algorithms and maps showing where the moon would be visible.
A set of predictions and maps can be seen at HM Nautical Almanac Office This shows the best time to see the previous new moon for the location requested at the standard time for the first three days of the new moon. It also gives an estimate of the ease of the sighting. For example, September 8 shows the best tim at 5:48 PM with a classification of F. September 9 is 6:04 PM with a classification of C, September 10 is 6:20 PM with a classification of A. The following month is shown with a set of three maps showing the area of the world which can see the moon, but it is more difficult to read. There is no data other than those two months.
There is a Java Applet which gives the location, moon age, and illumination for specific times at specific locations. Yerushalayim is not listed but the latitude (32.083333 N) and longitude (34.8 E) can be entered explicitly. Use the time about halfway (4/9) between sunset and moonset for the estimate being used.
Month Best time Pct Age
Cheshvan Oct 8, 1721 1.7% 1d 02h 33m
Kislev Nov 7, 1651 3.5% 1d 15h 55m
Cheshvan
For example, the astronomical molad for Cheshvan is 8:44 PM October 7. The moon times for October 8 are 6:12 AM rising and 5:26 PM setting. The noon % illumination is .8% at 11:52. The sunrise and sunset times are 5:37 and 5:16. Thus, it would probably not be visible at moonrise. The noon illumination on October 9 is 4.1 % at 12:49. I would therefore guess that the visibility during this time would be about 1%. This may be visible during the ten minutes after sunset and before moonset (about 17 hours after the astronomical molad). This would mean that Beis Din could not declare the chodesh until October 9 (since they must do so during the day). This would mean that the declared month would match the calculated month and Tishrei would have 30 days as the printed calendars show.
Kislev has the astronomical new moon at 6:52 AM on November 6, which seems to imply that eidus between moonset and sunset on November 6 might be possible however moonset and sunset are both 4:45 PM so it would probably be drowned out. If it was visible, Cheshavan would be a 29 day month, while if not (as is most probable) it would be a 30 day month as shown in the printed calendar
This seems to show that for at least Cheshvan and Kislev, the Sanhedrin would most probably declare the chodesh to be the same as our calculated calendar. It might be interesting to estimate what might happen during the rest of the months of the year and see what would have to be done to ensure that next Rosh Hashannah did not come out on one of the "forbidden" dates.
There are sites that calculate the percent visibility of the moon for a specific date and time. For example, the U.S. Naval observatory says
Although the date and time of each New Moon can be computed exactly (see, for example, Phases of the Moon in Data Services), the visibility of the lunar crescent as a function of the Moon's "age" - the time counted from New Moon - depends upon many factors and cannot be predicted with certainty. In the first two days after New Moon, the young crescent Moon appears very low in the western sky after sunset, and must be viewed through bright twilight. It sets shortly after sunset. The sighting of the lunar crescent within one day of New Moon is usually difficult. The crescent at this time is quite thin, has a low surface brightness, and can easily be lost in the twilight. Generally, the lunar crescent will become visible to suitably-located, experienced observers with good sky conditions about one day after New Moon. However, the time that the crescent actually becomes visible varies quite a bit from one month to another. The record for an early sighting of a lunar crescent, with a telescope, is 12.1 hours after New Moon; for naked-eye sightings, the record is 15.5 hours from New Moon. These are exceptional observations and crescent sightings this early in the lunar month should not be expected as the norm.
Obviously, the visibility of the young lunar crescent depends on sky conditions and the location, experience, and preparation of the observer. Generally, low latitude and high altitude observers who know exactly where and when to look will be favored. For observers at mid-northern latitudes, months near the spring equinox are also favored, because the ecliptic makes a relatively steep angle to the western horizon at sunset during these months (tending to make the Moon's altitude greater).
I would guess that they must have had some occurrance that managed to make it within 15.5 hours (in perfect conditions) in order to set the record. I saw that they did not say when the record was set. Phil Chernofsky has told me that the Israel New Moon Society uses a figure of 18 - 20 hours after the conjuction (astronomical molad) for the earliest possible visibility. I think that if we use the 18 hour figure to get the % of illumination we could calculate. Given that 29.5 days is 708 hours, 18 - 20 hours is approximately 5% - 6% illuminated. We can then use the illumination table to estimate if the moon would be seen around moonset on a particular day. This assumes that the eidim would see the moon between sunset and moonset only. Thus, I would add 18 hours to the conjunction and go to the next sunset time for that estimate.
The Naval observatory calculator generates a table for the year showing the percent illuminated for each day at midnight or noon in Universal Time or one of the U.S. timezones. This would be 7 hours earlier than the time shown for Yerushalayim. The South African Astronomical Observatory has a table of predictions showing where the moon would be visible as well as when it is first visible in South Africa. Another calculator is found at the fishing site http://www.noreast.com/moon/ This calculates the % illuminates at a set hour for a given day. It appears that this is also Eastern Time. Because the Muslims still use "eidus" as the start of their months, they have developed algorithms and maps showing where the moon would be visible.
A set of predictions and maps can be seen at HM Nautical Almanac Office This shows the best time to see the previous new moon for the location requested at the standard time for the first three days of the new moon. It also gives an estimate of the ease of the sighting. For example, September 8 shows the best tim at 5:48 PM with a classification of F. September 9 is 6:04 PM with a classification of C, September 10 is 6:20 PM with a classification of A. The following month is shown with a set of three maps showing the area of the world which can see the moon, but it is more difficult to read. There is no data other than those two months.
There is a Java Applet which gives the location, moon age, and illumination for specific times at specific locations. Yerushalayim is not listed but the latitude (32.083333 N) and longitude (34.8 E) can be entered explicitly. Use the time about halfway (4/9) between sunset and moonset for the estimate being used.
Month Best time Pct Age
Cheshvan Oct 8, 1721 1.7% 1d 02h 33m
Kislev Nov 7, 1651 3.5% 1d 15h 55m
Cheshvan
Monday, September 13, 2010
Why four out of five years (5771 - 5775) start on Thursday - Friday
The Jewish year has three possibilities for the number of days in a regular or leap year. The reason is that the lunar month is approximately 29.5 (twenty nine and a half) days long. If this was exact, then just alternating 29 and 30 day months would be correct. However, the exact average cycle is 29 days 12 hours 793 "parts" in length. A "part" is one in 1080 of an hour. The 793 "parts" converts to 44 minutes and 1 "part" as can be seen by looking at a chart of the molad announcements for the year. As a result, there are almost 15 minutes more than 29.5 days. This is handled by having the months of Cheshvan and Kislev be either 29 or 30 days and having the three possibilities of 29 and 29, 29 and 30, or 30 and 30. This calculation actually differs from the astronomical new moon as the year progresses. It is calculated by the total number of days in a lunar year and dividing by twelve. As a result, the actual molad can vary from the calculated value by as much as 10 hours.
Rosh Hashannah (first day) can never occur on Sunday, Wednesday, or Friday so that Yom Kippur cannot occur on Friday or Sunday and Hoshannah Rabbah can never occur on Shabbos.
Judaism 101 gives an interesting mnemonic for determining the leap years in the cycle using a piano keyboard
As can be seen the leap years are years 3, 6, 8, 11, 14, 17, and 19 (0).
This means that the pattern for these 5 years are L R R L R
A more detailed explanation is here
This makes the regular year have 353, 354, and 355 days ("adding 3, 4, or 5 days to the day of the week of Rosh Hashannah), while leap years have 383, 384, and 385 days ("adding" 5, 6, and 0). The Jewish year uses a 19 year cycle and the leap years can be shown by taking the year number as modulus 19. This year (5771) is year 14 of the cycle (year 19 of the cycle has modulus 0). The five years involved are thus 14, 15, 16, 17, 18 Year "17" is the next leap year. This year (a leap year) both Cheshvan and Kislev are 30 days so that next Rosh Hashannah (5772) will be also be on Thursday and Friday. The following year will have Cheshvan 29 days and Kislev 30 days (30 Kislev 5772 is 26 December 2011). This brings the following Rosh Hashannah (5773) to Monday and Tuesday. .
5773 will have 29 days in Cheshvan and Kislev which brings Rosh Hashannah back to Thursday again (from the modulus calculation above.) for 5774.
5774 is year 17 of the 19 year cycle and is again a leap year and again will have both Cheshvan and Kislev set to 30 days. This means that the following (regular) year of 5775 will again start on Thursday.
Since 5775 is not a leap year, Rosh Hashannah of 5776 will occur on Monday and since it is again a leap year (modulus number 0) with both Cheshvan and Kislev 30 days, the following year (5777) is again on Monday.
Larry Nussbaum pointed out by email the following five years starting with 5776 are L R R L R as well with the leap year again being "full" (both Cheshvan and Kislev having 30 days) This means that four out of those five years start on Monday, with the "off year" being Thursday. The last year of this pattern (5780) is year number 4 of the cycle, so 5781 (year 5), which starts on Shabbos, is also regular and 5782 starts on Tuesday.
This double pattern is quite rare. This appears to be to only such pattern (2 sets of 4 out of 5 back to back) in the past 247 years. In 5760 - 5764 we had 4 of 5 years with RH on Shabbos. There is no short cycle (like 19 or 28 years) when it comes to days of the week for yom tovim. The only cycle is a 247 year cycle (and that's not 100% guaranteed). Mr. Nussbaum also pointed out that the Tur has a 247 year calendar.
I saw this on the Mail Jewish mailing list, from Richard Fiedler
The above comment shows the "old moon" being visible the day before Rosh Hashanah by the fixed calendar. I realized as a result of a comment that I received that the Sanhedrin is based on eidus, which means that the eidim had to have seen the new moon. IIRC this is a minimum of six hours after the actual astronomic molad, which oscillates around the average announced molad. Actually, a member of the Israel New Moon Society has told me that the new moon would not be visible to the naked eye until it is at least 18 -20 hours old. The question would be when the actual astronomic "new moon" would be. I looked up on the internet and went to a planetary body calendar website to get these values. Note that the current rule is that Daylight time in Israel ends the Sunday morning before Yom Kippur. As a result, DST ends September 8. The times shown below are therefore in Daylight Savings Time.
Meridian Passing
Sep 4 Sep 5
Time: 11:42 A.M. 12:27 P.M.
Altitude: 65.6° 61.4°
Distance: 396,157 km 392,621 km.
Illuminated: 1.5% 0.1%
Phase: New at 2:37 P.M. Sep 5
I also checked and sunrise is 6:16 and 6:17 A.M. and sunset is 6:59 P.M. and 6:58 PM on those days. This seems to imply that IF the six hour time is correct, then the new moon would probably not be visible until 8:43 P.M. which is well after moonset. Note that the .1% illumination is at the meridian (which is "drowned out" by the noon sun) If the two hours before the new moon are linear to the 4 hours after the new moon, then the illumination would be no more than .2% and the six hours would be about .3% The previous days meridian shows 4.8% illumination which would make the moonrise illumination about 2.5%, with the sun still below the horizon. This may indeed allow it to be seen. In the case of the new moon, since the moon sets 15 minutes earlier than the sun, it would seem to be very difficult to see it. The illumination at the meridian for the day after the new moon (approximately 22 hours) is 1.0%. If the 18 hour estimate mentioned earlier is correct, this implies that the old moon would indeed have been visible.
When the Sanhedrin is reestablished, there will be a set of 30 day months until Rosh Chodesh gets co-ordinated with the eidus and astronomical molad rather than the fixed average molad that we announce now. As a result the Sanhedrin would have had to be established a number of months before this so that Rosh Hashannah could be on Shabbos (September 7) while Elul remained 29 days.
Rosh Hashannah (first day) can never occur on Sunday, Wednesday, or Friday so that Yom Kippur cannot occur on Friday or Sunday and Hoshannah Rabbah can never occur on Shabbos.
Judaism 101 gives an interesting mnemonic for determining the leap years in the cycle using a piano keyboard
This means that the pattern for these 5 years are L R R L R
A more detailed explanation is here
This makes the regular year have 353, 354, and 355 days ("adding 3, 4, or 5 days to the day of the week of Rosh Hashannah), while leap years have 383, 384, and 385 days ("adding" 5, 6, and 0). The Jewish year uses a 19 year cycle and the leap years can be shown by taking the year number as modulus 19. This year (5771) is year 14 of the cycle (year 19 of the cycle has modulus 0). The five years involved are thus 14, 15, 16, 17, 18 Year "17" is the next leap year. This year (a leap year) both Cheshvan and Kislev are 30 days so that next Rosh Hashannah (5772) will be also be on Thursday and Friday. The following year will have Cheshvan 29 days and Kislev 30 days (30 Kislev 5772 is 26 December 2011). This brings the following Rosh Hashannah (5773) to Monday and Tuesday. .
5773 will have 29 days in Cheshvan and Kislev which brings Rosh Hashannah back to Thursday again (from the modulus calculation above.) for 5774.
5774 is year 17 of the 19 year cycle and is again a leap year and again will have both Cheshvan and Kislev set to 30 days. This means that the following (regular) year of 5775 will again start on Thursday.
Since 5775 is not a leap year, Rosh Hashannah of 5776 will occur on Monday and since it is again a leap year (modulus number 0) with both Cheshvan and Kislev 30 days, the following year (5777) is again on Monday.
Larry Nussbaum pointed out by email the following five years starting with 5776 are L R R L R as well with the leap year again being "full" (both Cheshvan and Kislev having 30 days) This means that four out of those five years start on Monday, with the "off year" being Thursday. The last year of this pattern (5780) is year number 4 of the cycle, so 5781 (year 5), which starts on Shabbos, is also regular and 5782 starts on Tuesday.
This double pattern is quite rare. This appears to be to only such pattern (2 sets of 4 out of 5 back to back) in the past 247 years. In 5760 - 5764 we had 4 of 5 years with RH on Shabbos. There is no short cycle (like 19 or 28 years) when it comes to days of the week for yom tovim. The only cycle is a 247 year cycle (and that's not 100% guaranteed). Mr. Nussbaum also pointed out that the Tur has a 247 year calendar.
I saw this on the Mail Jewish mailing list, from Richard Fiedler
Mail.Jewish Mailing List
Volume 59 Number 26
Produced: Tue, 14 Sep 2010 01:15:16 EDT
From: Richard Fiedler
Date: Mon, Sep 13,2010 at 10:01 PM
Subject: Dates of Rosh HaShanah
Rosh HaShanah 2013 has another extremely unusual aspect. The Old Moon will be visible on Wednesday Morning Sept 4, 2013 and we will welcome in Rosh HaShanah Wednesday Night.
The Molad of Tishrei 2013 will be Yom Chamishi (Thursday), 16 hours 830 parts. This is under the window of the Molad Zaqen rule (18 hours causes a deferral of Rosh HaShanah) that normally prevents as Old Moon from being seen Erev Rosh HaShanah.
If you will join me in Jerusalem that week I will be on Mount Scopus at 5:10 AM when the Moon will rise. The Sun will rise at 6:16 AM. We will be seeing the cause of the Gemora of Rabban Gamliel and Rabbi Yehoshua (120 CE).
The reason for this is rooted in a very exceptional lunar orbit which is taking a path below the African Continent. Here is a link to the R H van Gent chart of Lunar Visibility for that date. https://files.me.com/richardfiedler/tfsa4d
The above comment shows the "old moon" being visible the day before Rosh Hashanah by the fixed calendar. I realized as a result of a comment that I received that the Sanhedrin is based on eidus, which means that the eidim had to have seen the new moon. IIRC this is a minimum of six hours after the actual astronomic molad, which oscillates around the average announced molad. Actually, a member of the Israel New Moon Society has told me that the new moon would not be visible to the naked eye until it is at least 18 -20 hours old. The question would be when the actual astronomic "new moon" would be. I looked up on the internet and went to a planetary body calendar website to get these values. Note that the current rule is that Daylight time in Israel ends the Sunday morning before Yom Kippur. As a result, DST ends September 8. The times shown below are therefore in Daylight Savings Time.
Moonrise and moonset in Jerusalem (DST)
| Date | Moonrise | Moonset |
|---|
|
|---|
|
|---|
Meridian Passing
Sep 4 Sep 5
Time: 11:42 A.M. 12:27 P.M.
Altitude: 65.6° 61.4°
Distance: 396,157 km 392,621 km.
Illuminated: 1.5% 0.1%
Phase: New at 2:37 P.M. Sep 5
I also checked and sunrise is 6:16 and 6:17 A.M. and sunset is 6:59 P.M. and 6:58 PM on those days. This seems to imply that IF the six hour time is correct, then the new moon would probably not be visible until 8:43 P.M. which is well after moonset. Note that the .1% illumination is at the meridian (which is "drowned out" by the noon sun) If the two hours before the new moon are linear to the 4 hours after the new moon, then the illumination would be no more than .2% and the six hours would be about .3% The previous days meridian shows 4.8% illumination which would make the moonrise illumination about 2.5%, with the sun still below the horizon. This may indeed allow it to be seen. In the case of the new moon, since the moon sets 15 minutes earlier than the sun, it would seem to be very difficult to see it. The illumination at the meridian for the day after the new moon (approximately 22 hours) is 1.0%. If the 18 hour estimate mentioned earlier is correct, this implies that the old moon would indeed have been visible.
When the Sanhedrin is reestablished, there will be a set of 30 day months until Rosh Chodesh gets co-ordinated with the eidus and astronomical molad rather than the fixed average molad that we announce now. As a result the Sanhedrin would have had to be established a number of months before this so that Rosh Hashannah could be on Shabbos (September 7) while Elul remained 29 days.
Monday, July 12, 2010
Mazal Tov
Mazal Tov to Mordechai and Shira Hocheimer on the birth on their son and my grandson מיכאל שמואל יעקב (Michoel Shmuel Yaakov) born on the Fourth of July (22 Tamuz).
מיכאל for my father-in-law
שמואל יעקב - for Rabbi Yaakov Weinberg, whose Yahrtzeit is Shiva Asar B'Tamuz (1 July 1999).
Also since he was born on the Fourth of July, Dod Shmuel (Uncle Sam) and "Yanky" (Yankee) Doodle are appropriate.
מיכאל for my father-in-law
שמואל יעקב - for Rabbi Yaakov Weinberg, whose Yahrtzeit is Shiva Asar B'Tamuz (1 July 1999).
Also since he was born on the Fourth of July, Dod Shmuel (Uncle Sam) and "Yanky" (Yankee) Doodle are appropriate.
Saturday, May 22, 2010
Calendar for Tzedukim
Rabbi Et Shalom in Mikra for Shavuos speaks of the calendar used by the minim to force the chagim (and every day of the month to always be on the same day of the week.
Professor Dick Henry has suggested using this calendar for modern times. He has suggested that the calendar be implemented at the start of a leap year so that the "new" and "old" calendars could merge seamlessly and that a year when January 1 starts on a Sunday be chosen. As a result, he is trying to get his "new" calendar implemented for January 1, 2012.
The actual year used by the Gregorian Calendar gives an average calendar-year length of exactly 365.2425 days which is within one ppm of the current length of the mean tropical year (365.24219 days).Using 364.242 as the year length, the calculation shows that the calendar has fallen behind by 27.324 days after 22 years and 28.566 days after 23 years. Thus, alternating 22 and 23 years causes the calendar to be ahead of the solar year by .11 days every cycle. As a result, after five cycles of this type (5 times 45 years = 225 years), the calendar is .55 days ahead of the actual year and a leap year after 23 years instead of 22 years would drop it back by .566 days instead of pushing it ahead by .676 days. As a result, the discrepancy becomes .01 days. This discrepancy should be good enough for the calendar.
Rabbi Et Shalom in Mikra for Shavuos speaks of the calendar used by the minim to force the chagim (and every day of the month to always be on the same day of the week.
The calendar displacement is 1.25 days a year, or 7.5 days every 6 years, which becomes 30 days every 30 years. As a result, a leap month of 28 days would be added every 22 years (6, 6, 6, 4). This actually puts the calendar ahead of the "real" time by .5 days every cycle. After 4 cycles, the calendar leads the solar time by two full days. The next leap month is after 24 years so that the calendar displacement is 30 days. The leap month of 28 days brings the calendar into "exact" adjustment with the Solar Year (28 days + the previous 2 day offset fixes the 30 day lapse after 24 years).
Among the many significant passages in the Mik'tzat Ma'aseh Torah is the Calendar of the community. Although there is much scholarly debate as to whether this calendar was ever put into practice, this solar calendar (!) is quite clearly spelled out and sheds much light on the motivation behind the Boethusian position in the debate regarding the date of the Omer offering and Shavu'ot.
The calendar (taken here from pp. 302-303 of Lawrence Schiffman's "Reclaiming the Dead Sea Scrolls", the source for much of the background information above) consisted of a 364-day year, constituting exactly 52 weeks. Each month had thirty days and, in order to keep the calendar in line with the equinoxes and solstices, a thirty-first day was added to every third month.
As a result of the exact weeks (with no remaining days) in this calendar, each Festival occurred on the same day of the week every year. [It is difficult to imagine how a calendar of this sort could ever be maintained without regular correction for the missing 30 hours every solar year; that is why, as pointed out above, many scholars claim that this calendar was never actually put into practice.]
Professor Dick Henry has suggested using this calendar for modern times. He has suggested that the calendar be implemented at the start of a leap year so that the "new" and "old" calendars could merge seamlessly and that a year when January 1 starts on a Sunday be chosen. As a result, he is trying to get his "new" calendar implemented for January 1, 2012.
The actual year used by the Gregorian Calendar gives an average calendar-year length of exactly 365.2425 days which is within one ppm of the current length of the mean tropical year (365.24219 days).Using 364.242 as the year length, the calculation shows that the calendar has fallen behind by 27.324 days after 22 years and 28.566 days after 23 years. Thus, alternating 22 and 23 years causes the calendar to be ahead of the solar year by .11 days every cycle. As a result, after five cycles of this type (5 times 45 years = 225 years), the calendar is .55 days ahead of the actual year and a leap year after 23 years instead of 22 years would drop it back by .566 days instead of pushing it ahead by .676 days. As a result, the discrepancy becomes .01 days. This discrepancy should be good enough for the calendar.
Thursday, December 03, 2009
Google bomb needed
Even though I actually do not post, I should set this up for a bit to help google bomb the haters at jewwatch.com. as a result, I am copying Meryl's post.
Put a permanent link to Judaism 101’s main page, and bring it back up above the haters. I’ve added it to my blogrolls. It’s a great site for information about Judaism and Jews. Here is a post talking about it and using the word “Jew” in the link.
Three little letters, and they cause so much anguish to the haters. Jew. Jew. Jew.
Put a permanent link to Judaism 101’s main page, and bring it back up above the haters. I’ve added it to my blogrolls. It’s a great site for information about Judaism and Jews. Here is a post talking about it and using the word “Jew” in the link.
Three little letters, and they cause so much anguish to the haters. Jew. Jew. Jew.
Monday, April 03, 2006
Thursday, February 16, 2006
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