The PETA website (accessed Aug 2, 2011) states:

“Jews are prohibited from wearing leather on Yom Kippur.”

“Jewish Vegetarians of North America President Richard H. Schwartz explains “One reason is that it is not considered proper to plead for compassion when one has not shown compassion to the creatures of G-d, whose concern extends to all of His creatures.” (see his website)

“Many rabbis through the ages have shared this view. Rabbi Moses Isserles (c. 1528-1572), aka the Rema, said, “How can a man put on shoes, a piece of clothing for which it is necessary to kill a living thing, on Yom Kippur, which is a day of grace and compassion, when it is written ‘His tender mercies are over all His works’?” (Psalms 145:9).”

I came across this while researching my Fall 2011 Jewish Action column on the misconception that it is prohibited to wear leather items, such as a leather belt or yarmulke, on Yom Kippur and Tisha B’av (see here). Actually, as I show in that article, there is no general prohibition against wearing leather on Yom Kippur. Furthermore, there is not even a prohibition of wearing “leather shoes.” Rather, the prohibition on Yom Kippur and Tisha b’Av is wearing “shoes”, which in normative halacha are defined as leather shoes, although not everyone agrees to that and many authorities assume the prohibition is to wear any protective shoe.[1] Thus, not wearing leather shoes has nothing to do with compassion to animals, but is rather an innui for us, not compassion for animals. In addition, these rules also apply on Tisha B’av when there is no “pleading for compassion” and when we also wear leather at Mincha – when we put on tefillin.

But most intriguing was this “quote” from the Rema that PETA cited from Richard H. Schwartz. It did not sound like the Rema, and indeed it does not exist. So I proceeded to track down its origin. (It seemed unlikely that Richard Schwartz would simply fabricate a quote.) The Rema (OC 223:6, cf KSA 59:13) does quote that verse, but in a different context. He records that it is customary that when someone acquires a new garment people wish him well by saying “tivale v’tichadash – may you wear it out and get a new one”, however some people say not to say that on leather garments because then another animal will need to be killed and God is merciful on all his creatures. Amazingly, the Rema then rejects that argument as weak. Thus, in the only place where the Rema cites that pasuk he rejects it as a reason.

So where did PETA find this “quote”? In Schwartz’s book Judaism and Vegetarianism (p. 21 in the 1988 ed.) he includes this –

– and in footnote 34 he tells us that his source for this amazing quote is Samuel Dresner, The Jewish Dietary Laws (p. 33-34, 1966 ed). Unfortunately, Schwartz misread Dresner, misunderstood where quotes ended, did not look up Dresner’s source, and thereby fabricated a quote from the Rema.

Dresner’s point of departure was the law cited above regarding the good wishes offered upon putting on a new garment. He then cites a novel reason for the prohibition of leather shoes, but does not give much detail about his source. It turns out that this reason is found for the first time in Toldot Esther, a commentary by Rabbi Shlomo Tzvi Shück (1844-1916) on the Siddur haMinhagim of Rabbi Yitzchak Isaac Tirna (64a in the 1880 ed. link).

Dresner may or may not have understood where the quotes end, but it is indeed confusing in his English rendition.

He quotes the Rema regarding leather clothing along with the pasuk from Tehillim (and following Shick, leaves out the Rema’s rejection). He then quotes the Rema regarding no shechiyanu on shechita and, without opening or closing quotes, proceeds into Shick’s novel reason for not wearing leather shoes on Yom Kippur.

Rav Shick (see scan below) was very clear in how he explained himself. He wrote that he had his way of explaining the prohibition of wearing (leather) shoes on Yom Kippur. He then cited the Rema on new clothes and the Rema on shehechiyanu on a first occasion, and based on those asked rhetorically how on Yom Kippur which is a day of chesed v’rachamim one can wear a garment that necessitated killing an animal. He had no fabricated quotes, but he does offer a perplexing explanation for something that was not looking for one. As noted above, the prohibition on Yom Kippur is to wear shoes, which some people understand to mean leather shoes. But the prohibition is derived from the fact that going shoeless is an innui. It also therefore applies on Tisha b’Av and to mourners, obviously unrelated to chesed v’rachamim. Furthermore, leather may be worn on Yom Kippur.

Thus, a novel, difficult to understand explanation for a straightforward prohibition has spawned a fabricated quote from the Rema that is now fairly widespread on the web.

Sukkot is fast approaching. For many this means selecting a “mehudar” etrog. Depending upon where one is this task can involve not only selecting an etrog with or without a pitum, bumpy or smoother, with or without a gartel, or a host of other considerations, but also selecting which type, Berman or Hazon Ish. Indeed, today, there are variety of types of etrogim identified by the farm or personalities that have ostensibly certified them as Kosher for use during the holiday. But, how do we know that any of these types are preferred? Where did these etrogim originate? Are they really Kosher?
Until recently, the answers to many of these questions have been shrouded in mystery. Sure one may have been told that so-and-so decided (mostly by merely looking at a particular tree) this etrog is Kosher. Today, however, Zohar Amar, who has written extensively on agriculture and other issues involving mesorah as it relates to Kashrut, has published a book where he investigates these questions, Etrogei Eretz Yisrael, Israel, 2010, 85 pp.
In reality, this latest book complements his book published last year discussing all the four species, Arbat ha-Minim, Israel, 2009, 101 pp. The earlier book, as it relates to etrogim focuses on how and when we identified the etrog with the biblical commandment of “prei etz hadar.” Amar seeks to disprove the notion that etrogim were not native to the Middle East until far after the Jews were present. This is important as some want to argue that the use of etrogim for araba minim is of late origin and thus undermine the mesorah associating etrog with prei etz hadar. Amar’s thesis is can be summed up using the talmudic expression “lo raenu enu rayah.” That is, much of what has been said about this point is predicated on the lack of etrogim seeds or evidence that can be dated to an early period – i.e. when Jews were in Israel practicing the Torah.
Amar provides the earliest evidence that we have of etrogim and their use on Sukkot. For example, etrogim appear on some Jewish coins and in mosaics. While some may associate the “gartel” or figure eight shaped etrogim with hassdim (probably because some hassidim wear such belts all year-round), in reality, many of these early depictions show etrogim with a gartel.
Additionally, Amar discusses the development of using etrogim from outside of Israel and then their importation and eventual grafting of those etrogim. The reason these foreign etrogim were used were because, for the most part, etrogim that are indigenous to Israel aren’t what we would consider mehudar today. Typically they lacked the pitum and weren’t shaped nicely and were smoother than our bumpy etrogim. Thus, some began to use etrogim from outside of Israel. This in turn created a controversy as to whether those etrogim were Kosher as well as whether there is a preference for Israeli etrogim over those from outside of Israel.
As part of this controversy the issue of grafted etrogim became a much larger issue. Indeed, the issue of grafting etrogim doesn’t appear in Jewish literature until 16th century. Amar, discusses the development and application of this concept as it relates to etrogim.
Returning to Amar’s latest book, Etrogei Eretz Yisrael. This time around Amar turns his focus to the mesorah of Israeli etrogim. He has extensively researched this topic and his research included visiting the etrogim farms and speaking with the farmers. What emerges is that for most of the etrogim available today, the best we can trace their pedigree is 100 years. For many, it is less than that. That. is, while many claim significantly longer pedigrees, the stories fail to match with fact. That is not to say that today’s etrogim aren’t Kosher or that many are grafted, only that we don’t have evidence that today’s etrogim are the same as were used more than 100 years ago. Amar concedes that more research, including genetic and other scientific testing is necessary to determine which etrogim are pure and ungrafted.
In all, this latest book is an important one as it sets the baseline for further research regarding etrogim, and, additionally, provides more background on the specific types of etrogim currently available in the marketplace today.
The books are distributed by Girsa and Shalem in Israel and is available at Beigeleisen in the US.

This is the last of four posts based on a forthcoming monograph by Dr. William Gewirtz that addresses the period of bein hashemashot, the most fundamental area of dispute in the area of zemanim.

The previous post summarized the main sections of the monograph; this post summarizes some of the areas of innovation and is followed by concluding observations.

Much of what was proposed tacitly made two basic assumptions:

 First, both halakhic practice and its conceptualization were influenced by the migration of Jews from the Middle East to Central and Northern Europe during a period when the impact of latitude on zemanim was not yet understood.
 Second, with the subsequent growth of clocks, increasingly, halakhic practice was specified using time in preference to observation of natural events.

It is probable that both of these factors were consequential. (Increasingly, time replaced observation as the basis for specifying halakhot. Preference for a time based halakhic rule (72 minutes, for example) over the underlying event from which the interval of time was derived has become increasingly common. More subjectively defined phenomena like misheyakir or the approximate boundary between a medium and a small star were less often utilized and, as a result, became less well understood.)

The PDF of the entire epilogue is attached. The epilogue includes a complete list of the innovations that have been proposed and a more extensive version of post 3. A subset of the innovations proposed and a concluding example and remarks follow below:

1. The dispute between the geonim and Rabbeinu Tam revolves around placing the interval of bein hashemashot, whose length is the time to walk ¾ mil, within the interval between sunset and tzait (kol) hakokhavim whose length is the time to walk 4 mil. It is normally assumed that:

 the opinion of the geonim places bein hashemashot at the start of the interval, while
 Rabbeinu Tam places it at its end.

Those two alternatives represent opposite extremes. Two modifications were suggested throughout:

 First, separate the dispute between the geonim and Rabbeinu Tam into two distinct components; the first concerns the beginning and the second the end of the bein hashemashot period, subject to a constraint on the length of the bein hashemashot interval.
 Second, assume that there are multiple hybrid / intermediate positions, bracketed by these two alternatives. (These positions might be more properly characterized as variants to the position of the geonim as they are all much closer to their bein hashemashot interval.)

This allows:

 an interpretation of the gemara in Shabbat similar or more likely identical to that of the overwhelmingly compelling position of the geonim relative to the end of the bein hashemashot period,

 while defining the beginning of bein hashemashot using a variant of the textual approach of the Shulchan Aruch and Rabbeinu Tam.

While I have not seen this conceptualization formulated explicitly (Throughout R. Kapach’s commentary on Mishneh Torah, however, he asserts that this is the position of Rambam.) in the classic halakhic literature, practice and a number of pragmatic opinions are supportive of such an approach. This approach impacted sections 5 – 8 and is central to many of the suggested innovations. The opposite implication:

 Anyone who rejects the start of Shabbat precisely at or even some number of minutes after sunset must embrace the approach of Rabbeinu Tam

which does not follow logically, is often found in the literature.
2. It is preferable to read the gemara in Shabbat assuming that all opinions vary insignificantly concerning the end of Shabbat; this is the opinion of almost all rishonim and independent of the position of Rabbeinu Tam. The gemara’s focus is primarily on the beginning of bein hashemashot on Friday evening, and that point is in dispute.

3. Modern practice, contemporary halakhic literature, as well as colloquial idiom, typically refers to time intervals calculated from sunset. Assuming that way of thinking when reading specific sources, we fail to consider that the gemara, various rishonim and achronim (we referenced R. Lorberbaum, R. Adler and R. Sofer) refer to intervals of time counting backward from the end of Shabbat as well, not always counting forward from sunset.

4. Rabbah’s interval, the time to walk ¾ mil, is more likely an upper bound on the length of bein hashemashot (the length of bein hashemashot in the summer) counting back from the point of chashekha versus a lower bound (the length of bein hashemashot in the spring) counting forward from sunset. Treating the gemara in Shabbat similar to the gemara in Pesachim as referring only to the (fall and) spring equinox is unnecessary when thinking of the interval as a practical upper bound. (First suggested by the Gaon in OC 261 and widely assumed in recent halakhic literature. Note while the gemara in Pesachim assumes an average that occurs at both the spring and fall equinox, the Gaon’s argument assumes, not an average, but a minimum and referring only to the spring, but not the fall equinox. No rishonim, who limit the gemara in Pesachim to the equinox periods in the fall and spring, make any such assertion with respect to the gemara in Shabbat. A maximum, as opposed to a minimum, would apply year round, as one might also conclude from the lack of commentary.) All the other measures in the gemara of chashekha, the appearance of the horizon, or the visibility of three stars apply year-round. Some of the arguments in favor of such a position include:

 The gemara in Shabbat is discussing Friday night and the beginning of bein hashemashot, as opposed to its end. If the time to walk ¾ of a mil were a minimum, counting forward from the beginning of bein hashemashot, it would address the end of bein hashemashot and the end of Shabbat, as opposed to its beginning.
 The three fractions of the time to walk a mil that are given as alternatives for the length of bein hashemashot would all have identical semantics counting back from the assumed point of chashekha.
 The interval of bein hashemashot is of practical consequence providing a useful upper-bound as opposed to a theoretical lower bound.
 If someone were countering the position of Rabi Yosi, who says bein hashemashot is instantaneous, it is more likely that he would say that it can be as long as opposed to as short as.

5. Shmuel’s assertion about 1, 2 and 3 stars is likely to mean that one star can still occur during daytime, but two stars only (If we assume that bein hashemashot begins 14 -15 minutes after sunset then “only” should be replaced with “almost always.” Though proposed by R. Kapach in his interpretation of Rambam, it would make Shmuel’s assertion slightly less useful. The suggested meaning of Shmuel’s statement is more elegant if we assume that bein hashemashot starts at most 12 – 13 minutes after sunset in the Middle East.) appear after the beginning of bein hashemashot (whose start may also precede the appearance of the first star) and three stars confirm that the transition to the next day has occurred.

6. Moving the beginning of bein hashemashot forward from sunset even according to Rabbah, a variant of the generally assumed opinion of the geonim, successively solves the following issues:

 at 4 – 5 minutes, the minimal time reported as the custom of Jerusalem as well as the opinion of R. Shneur Zalman of Liadi, the point when the sun disappears from the highest elevations around Jerusalem, Shmuel is consistent at least in a limited sense with R. Yosef while remaining completely inconsistent with Rabbah.
 at 6 minutes, the opinion of R. Chaim Volozhiner and the appearance of a single star in the spring to an expert observer, Shmuel is more easily consistent with R. Yosef but consistent with Rabbah only in a limited sense.
 at 7 – 15 minutes depending on a variety of factors, Shmuel is entirely consistent with Rabi Yehudah and the time to walk ¾ mil can be easily considered a practical upper bound.

7. While many equate and then struggle to resolve Rambam’s approach to Shabbat and Kiddush Hachodesh; I assume they are dissimilar. (Why so obvious an approach was not considered may be related to the assumption that safek chashekha and bein hashemashot are coincident. Though the two notions may be practically coincident, they are certainly not conceptually the same. For those following an opinion akin to the geonim for the end of Shabbat, they may not even be practically coincident. Within the halakhic literature there are differing opinions about the relationship between safek chashekha and bein hashemashot.) In both instances, Rambam considers chashekha as defining the end of a day. For a beit din declaring the beginning of a new month, Rambam sees no necessity to impose an interval of bein hashemashot. Thus, Rambam in hilkhot Kiddush Hachodesh states the halakha in (2:8) and then the recommended practice in (2:9). However, in hilkhot Shabbat, as noted in our opening paragraph, when dealing with a community, Rambam utilizes a notion of bein hashemashot, an interval that he defines practically as opposed to theoretically.

8. While the appearance of the horizon and the visibility of stars are difficult to reconcile with the opinion of Rabbeinu Tam, the argument between Abaye and Ravah, looking east and west at the same point in time, is most challenging. I cannot conceive of anyone in the Middle East detecting any change looking at the eastern sky 50 – 60 minutes after sunset. This is perhaps the greatest challenge to Rabbeinu Tam’s definition of the end of Shabbat.

9. It is probable that R. Adler’s 24/35 minute period of bein hashemashot is computed counting back from Rabbeinu Tam’s conceptual end of Shabbat. The alternatives, either counting back from the time that the Frankfurt community typically observed as the end of Shabbat or counting forward from any point in time, are less plausible. While this formulation faces textual challenges, other attempts to explain R. Adler’s opinion including that assumed by the editors referenced by Dr. Leiman as well as multiple suggestions of R. Benish face far more difficulty.

10. A number of recent essays on zemanim, including those by R. Kotler and R. Willig, suggest specific dependencies linking

 the dispute between the geonim and Rabbeinu Tam,
 the dispute whether shaot zemaniot are calculated from sunrise or from alot hashachar,
 and in the case of R. Willig even the time to walk a mil.

I see no such logical dependency and found that custom and / or authorities supported almost every possible combination of alternatives.

11. It is puzzling that when calculating the opinion of the Magen Avraham / Trumat Hadeshen attention to the impact of latitude and/or seasonality is rarely taken into account. In addition to morning zemanim, like the latest time for kriat shema, being earlier, this approach would also provide an alternative for plag haminkha (that many communities in US latitudes might find useful.) Similarly, adjusting alot hashachar would often imply an earlier start for those fast days that start at daybreak (particularly the 17th of Tammuz.) (While not a Magen Avraham specific issue since alot hashachar is applicable according to all opinions, invariance of the 72/90 minute interval is likely inherited from similar practice applied to the position of Rabbeinu Tam with respect to the end of Shabbat which then influenced the calculation of shaot zemaniot according to the Magen Avraham. (See summary for category 3. where this is further explained.) Though conceptually challenging in both contexts, a fixed 72/90 minutes does not create obvious observational issues, except for alot hashachar and only at latitudes further from the equator, like northern Europe.) That would avoid a practice that allows eating on the morning of a fast as late as (or even after) the time of misheyakir.

A concluding example:

The migration of Jews from the Middle East to other locations required adjustment in practice that often necessitated creating concrete concepts in areas that might have otherwise been left unexplored. That process contributed to a wealth of material with which many poskim have had to grapple. Both the categorization and the new approaches that have been proposed should make this vast halakhic literature more understandable.

As I mentioned in the preamble, criticism within the rabbinic literature has been muted, (There are a few very notable and important exceptions.) and potential inaccuracies have often not been identified and discussed adequately. As a result, it is impossible (perhaps even for great poskim who are unacquainted with astronomy or the impacts of season and /or latitude) to read the literature without intense effort.

Let me illustrate using the most widely followed posek of our times, and conclude with a few words, which I hope will be taken as they are meant. I choose R. Feinstein because I assume that many will conclude that if his responsa illustrate my concerns, I could have easily chosen any number of other poskim.

Consider five decisions of R. Feinstein:

1. In the New York area, Shabbat ends 50 minutes after sunset even in accordance with Rabbeinu Tam.
2. One can pray as early as 90 minutes before sunrise under special circumstances.
3. Perform a brit the following week on Wednesday, for example, for a baby born late Wednesday afternoon until 9 minutes after sunset.
4. In the New York area, allow specific activities forbidden only at a rabbinic level on the Shabbat until 40 minutes after sunset on Friday.
5. Unlike other zemanim, chatzot is always at the same time (that varies by location) and does not vary throughout the year.

Summarizing issues discussed previously, these tshuvot are challenging in six (R. Feinstein’s mention of the time to walk 4 mil as 96 minutes while given no practical consequence is also problematic.) different areas:

1. Like R. Pimential approach to Holland, R. Feinstein’s derivation of 50 minutes for New York, reasons by analogy on the appearance of stars, using Lithuania as his base for 72 minutes. Were R. Feinstein to have used Babylonia, certainly a more logical choice, he would undoubtedly have reached a radically different conclusion. R. Willig expresses a similar point, albeit less directly. (This issue was raised directly in a recent sefer by R. D. Heber, Shaarei Zemanim, page 90.) Generally, this psak is quoted without hesitation or comment. (Perhaps new meaning for the term chassid shoteh can be ascribed to the publishers of a sheet I picked up at the Kotel, that provide R. Feinstein’s 50 minute zman for New York for use in Jerusalem.)
2. As R. Feinstein is following the conceptual approach of Rabbeinu Tam, then the end of Shabbat and the time for alot hashachar ought to be treated identically. Instead, R. Feinstein:

 relies on a 22.5 versus 18 minute time to walk a mil for alot hashachar but never even suggests a 22.5 minutes based stringency for Shabbat,
 adjusts only Shabbat’s end but not alot hashachar based on latitude (R. Feinstein does briefly mention the possibility of latitude adjustments for alot hashachar in the tshuva but chooses not use it.) and
 never addresses the relationship between his rulings that, according to the opinion of Rabbeinu Tam that he is following, are conceptually linked.

3. Adjusting zemanim based on latitude to correlate to a physical occurrence like the appearance of stars or the degree of light is strongly supported. However, directly adjusting the time to walk a mil whose length is linked neither to latitude nor to season by location, has no logical basis and leads to conclusions that are in fundamental conflict with observation. (While there exists imprecise language in the literature prior to R. Feinstein that talks in terms of such adjustments, using it as a basis for a psak that reduces / equates 13.5 minutes to 9.375 minutes is inexplicable. As we have noted, this is logically equivalent to asserting a watch that moves 72 minutes in Lithuania, only moves 50 minutes in New York.)

4. Deriving the beginning of bein hashemashot by subtracting from the time that Shabbat ends is common in psak and rooted in the text of the gemara. However, it requires that the end of Shabbat be accurately established. The time that R. Feinstein uses for the end of Shabbat is his (and R. Y. M. Tukitzinsky’s) calculation that is among the most stringent methods for calculating what is already a stringency based on three small stars and not the point that the gemara uses, three medium stars. This is further impacted by R. Feinstein’s use of a “truncated / adjusted” time to walk ¾ mil of 9.375 minutes (as opposed to 13.5 minutes) for the New York area, resulting in a significant leniency. To be concrete, as opposed to the 40 minutes (50 minutes and subtracting 9.375 minutes for bein hashemashot) after sunset that R. Feinstein derives, three medium stars are visible approximately 27 – 32 minutes after sunset, safek chashekha and certainly bein hashemashot precedes that point by some number of minutes. Of course, R. Feinstein, operating within the framework of Rabbeinu Tam, may not consider 50 minutes as a stringency.

5. Chatzot varies slightly day to day (given the tilt of the earth in its orbit) according to the all methods for calculating the hours of the day; the variation is approximately 20 minutes in the New York area.

6. At a very fastidious level, R. Feinstein calculates adjustments based on latitude without regard for the non-linear relationships that exist between the duration of different sub-intervals of bein hashemashot.

In all but the third item above, R. Feinstein had an extensive literature from which to derive support. As was noted, R. Soloveitchik carefully recast the opinion Rabbeinu Tam to avoid these and other issues. However, he ended up with a conceptual approach to Rabbeinu Tam as well as a personal chumrah, which is almost unheard of in the halakhic literature and widely divergent from practice. However, given that this is an area with a long tradition of practice, great poskim, of which R. Feinstein is a unique example, exhibit an impeccable sense (In addition to or perhaps as a result of siyatta di’shemaya.) that guides them in how to decide. I remain struck by the accuracy of the psakim, independent of their problematic rationale. Let us reexamine the five decisions and how they might be alternatively justified:

1. Shabbat ends 50 minutes after sunset in the New York area. Despite this not being the conceptual opinion of Rabbeinu Tam, as R. Feinstein assumes, it is precisely the opinion of the geonim as calculated by R. Yechial Michal Tukitzinsky, the first major contemporary figure to write extensively on this topic combining knowledge of both halakha and astronomy. (R. Belsky’s (re)interpretation of R. Feinstein makes this correspondence precise. See the commentary supporting the www.myzmanim.com website.)
2. One can pray as early as 90 minutes before sunrise in special circumstances. A latitude and seasonal adjustment of 90 minutes provides a basis for yet greater leniency. Beyond the reliance on a 22.5 minute mil, 90 minutes in New York is close to both the scientific point of first light (approximately 90 to 120 minutes), and, more importantly, a latitude/season adjusted 72 minutes (approximately 80 to 110 minutes). The fact that R. Feinstein was willing to rule so differently on the end of the Shabbat and alot hashachar aligns with tradition, albeit in conflict with the conceptual viewpoint of Rabbeinu Tam.
3. Perform a brit the following week on Wednesday, for example, for a baby born late Wednesday afternoon until 9 minutes after sunset. Clearly, this psak is in perfect alignment with the views developed and similar to the tradition of Jerusalem over the generations that assumed that a baby born a few minutes after sunset has his brit on the same day the following week. (See Minhagei Eretz Yisrael by R. Yaakov Gliss, pages 102 and 282 who mentions 4 – 5 minutes and Zemanim Kehilkhatam by R. Boorstyn, chapter 2, section 1, footnote 7, who claims that R. Shmuel Salant, would rule that a baby born after sunset but before the call of the mugrab, seven to ten minutes after sunset, has his brit on the same day the following week.) Even rejecting Rabbeinu Tam’s late end of Shabbat based on the overwhelming arguments of the Gaon and others, a start to a day a few minutes after sunset is supported by generations of practice. Even R. Feinstein’s reliance on Rabbeinu Tam for a slightly delayed beginning to bein hashemashot is often rejected.
4. Allow specific activities forbidden only at a rabbinic level on the Shabbat until 40 minutes after sunset. Perhaps the most challenging given the undisputed assumption that the gemara meant bein hashemashot to extend back from three medium stars (a depression angle of about 6 degrees) versus R. Feinstein’s roughly 8.5 degrees and R. Feinstein’s use of a “truncated / adjusted” 9.375 minutes to walk ¾ mil. Nonetheless, being exceedingly liberal with respect to a rabbinic prohibition, especially, in the face of need, has a long tradition. Unfortunately, in most, if not all seasons of the year, 40 minutes after sunset, is well past the point of chashekha, in the New York area.
5. Chatzot is always at the same time. As with R. Feinstein’s 50 minutes, there is a need for seasonal adjustment. It appears, like a number of Rabbis who oppose this type of complexity in psak, R. Feinstein’s tradition was to use a single time.

On the first three rulings, R. Feinstein’s psak can be easily justified on other grounds. The last two are somewhat less critical and more problematic. However, it is often dangerous for Rabbis to apply or extend elements of R. Feinstein’s logic to other areas where zemanim are critical without his innate sense of psak.

Final Comments:

This monograph was intended to address seminal issues relevant to bein hashemashot without covering in depth many important sub-topics. Hopefully, the approach and observations will make this vast literature easier to study. While I did not want to address explicitly either philosophic issues or practical issues of psak, I suspect that my personal opinions on both are clear. I was strongly motivated to defend minhag Yisroel, a mimetic tradition that for many centuries, even until the Second World War, relied on the opinion of Rabbeinu Tam in many parts of Europe.

As I studied this topic, I was repeatedly revisiting three issues:

 If in ancient times, sunset, a very easily identified occurrence, was considered the precise starting time for Shabbat, how could it have ever been forgotten and / or abandoned? If Shabbat started sometime after sunset, then the position of Rabbeinu Tam and an overwhelming number of rishonim is more plausible. As Jews migrated northward, the required beginning to Shabbat separated even further from sunset, particularly if bein hashemashot was thought to have an unchanging maximum length – the time to walk ¾ of a mil.

 If observation challenged only Rabbeinu Tam’s opinion while leaving the approach of the geonim free of any issues, why did major figures living in southern Europe and even the Middle East, including Ramban and (likely) R. Yosef Caro, adhere to Rabbeinu Tam’s opinion?

 How could generations of practice that relied on the opinion of Rabbeinu Tam or some related variant be so easily discounted? In my mind, the modern bias to treat sunset as a given (and reject even R. Feinstein’s limited reliance on the position of Rabbeinu Tam) is unwarranted.

I hope that what I have written, at least partially, addresses these questions.

The approach developed posits that bein hashemashot begins after sunset, later than many assume, while its end is somewhat earlier than current practice. (R. Y. C. Sonnenfeld’s tshuva 33 (an approbation to a sefer on zemanim) on this topic is remarkably supportive. While speculating that we may have to wait for Elijah to defend the fundamental difficulties with Rabbeinu Tam’s end to bein hashemashot and Shabbat, he raises issues with the approach of the Gaon as to the beginning of bein hashemashot from texts of gemara that imply that the day extends past sunset. While suggesting that we follow both chumrot and stating a personal preference not to attempt to decide on a matter so long in dispute, he expresses hope that this will be clarified one day. I believe that I have taken a step in that direction. In any case, regardless of his suggested practice, like this monograph he raises issues with both the end time of Rabbeinu Tam and the start time of the geonim. While R. Sonnenfeld suggests that one adopt the stringencies of both positions, the approach developed and generations of practice often made use of the leniencies of a hybrid approach.) While some will contend that the criticism, suggested innovations, and conclusions do not exhibit sufficient deference to recent generations of psak, I hope that this monograph demonstrates a commitment to integrity, clarity, simplicity, consistency with basic astronomic observations, faithfulness to basic texts and respect for generations of halakhic insights and in particular, practice.

In summary, a fulsome defense for a later start to Shabbat is anchored on three points:

1. Mishetishkeh hakhamah refers to a point after sunset.

2. The time to walk ¾ of a mil is the maximum length of bein hashemashot not the minimum.

3. When applying the gemara’s interval of bein hashemashot to other locations, its length need not be extended.

The first is the preferred reading of the gemara in Shabbat according to most rishonim. The second is strongly supported by simple logic and arguably by the statement of Shmuel, though certainly at variance with the prevalent contemporary interpretation. The third is clearly debatable, but the viewpoint of some major poskim. All three are needed to defend fully historical practice. However, even the first, or certainly the first two points, should influence contemporary psak in extenuating circumstances.

Those familiar with R. Kapach’s approach to Rambam throughout Mishnah Torah, will recognize that his conclusions as to Rambam’s position on the twilight period and much of this monograph are consistent. While R. Kapach’s approach tacitly assumed stars, as opposed to darkness, as defining both the beginning and the end of bein hashemashot, something I believe that Rambam did not support, R. Kapach’s practical conclusions and insights into Rambam aligns Rambam across Mishnah Torah closely with the ideas that have been developed. (1. R. Kapach also insists on bein hashemashot beginning at 15 minutes after sunset, something we are not convinced that Rambam necessarily maintained. 2. As has been mentioned previously, objections to the approach of the geonim derive from sugyot where sunset does not appear to be a precise delimiter. Similarly, despite Rambam’s clear identification with the position of the geonim, some try to align his position with Rabbeinu Tam based on the fact that he did not consider sunset as critical as many assumed that an approach like that of the geonim had to maintain. As has been argued throughout this monograph, the “either-or” assumption of either Rabbeinu Tam or the geonim, without intermediate positions is an assumption that I find neither conclusive nor correct. 3. Building on R. Kapach’s approach, a future paper will attempt to demonstrate that Rambam maintained a hybrid / intermediate position, similar to the position of the geonim, consistent with the text of the gemara, astronomic observation and supportive of the approach taken in this monograph.)

It should also be clear, that while their rationales were entirely different, many poskim who in practice followed R. Pimential’s approach supported a position akin to what has been suggested throughout the monograph. In practice, they allowed work after sunset proper and awaited only three (small) stars, not a full 72 minutes. As well, they would never allow work on Friday, anywhere near as late as Rabbeinu Tam’s conceptual position would suggest.

Both the practice suggested by these poskim and R. Kapach’s interpretation of Rambam conceptually aligns with the approach developed throughout this monograph.

Clearly, in the study of zemanim, one has to “look up” as well as “look in.” Over the last few hundred years, careful observation of the skies has often been replaced with a fixation on time and timepieces. This contributed a false sense of accuracy as opposed to enhanced clarity to an already complex area.

This is the third of four posts, from a draft of a forthcoming monograph by Dr. William Gewirtz that addresses the period of bein hashemashot, the most fundamental area of dispute in the area of zemanim. What is proposed is an astronomically accurate hybrid position between the diametrically opposed conceptual views of the geonim and Rabbeinu Tam. That position justifies, to varying degrees, the practice of countless generations of European Jewry that started Shabbat well after sunset on Friday evening. Though often ignored in modern times, practical equivalents of this hybrid position have had major adherents throughout the generations. Our goal is to demonstrate that such a position is not just plausible, but in fact the preferred reading of the gemara in Shabbat, the primary text concerning bein hashemashot.
The attached PDF (click here to download) contains the 9 main sections of the monograph. Sections 5, 7 and 8, focused on reading the text of the gemara in Shabbat consistent with observation, detail the core thesis. This post is a commentary on each of the nine sections; unlike the PDF, it takes much wider latitude for conjecture. The next and last post summarizes some major areas of suggested innovation, contrasting the approach taken with an illustrative example of contemporary psak (the various rulings on zemanim of R. Feinstein), before making some closing observations.
Commentary on the 9 sections:

1. How many mil does one walk during the period from sunrise to sunset? What is the time required to walk a mil? – 18, 22.5, 24 minutes, etc.

Except for Rambam and R. Ovadiah Bartenura, few maintain 24 minutes. Both of the other major opinions have significant support. Some geonim and rishonim likely maintained an 18 minute interval. However, many if not almost all later rishonim, particular those following Ramban, adhere to 22.5 minutes. Interestingly, by the time of the Shulchan Aruch most authorities are united around 18 minutes, with a small number of achronim strongly supporting 22.5 minutes.

When I started studying this topic, I was convinced by the overwhelming arguments presented by Prof. Levi based on both the text of the gemara and the opinion of many rishonim, that 22.5 minutes should be strongly preferred. However, 18 minutes also appears well supported. Geography (the distance from Modiin to Jerusalem, for example) seems to support more mil walked per day (even 40 being difficult.) As well, the assumed similarity of the fractions 1/10th and 1/6th used by the gemara in Pesachim would place the twilight period of either the time to walk 4 or 5 mil outside of the daytime period of the time to walk 40 or 30 mil; 5 mil external from 30 mil (1/6th) should imply that 4 mil is external from 40 mil (1/10th.) Arguments in favor of 18 minutes from anyone maintaining 72 minutes, almost all of R. Yosef’s examples, while not conclusive are highly likely. An assumed added vav in the text of the gemara in Pesachim (Our text of the gemara reads “teidah…“u”mealot hashachar” in the second such phrase addressing the interval between dawn and sunrise. The vav does not appear in certain older texts.) when referring to the twilight periods might have been intended to clarify or to lend further support to 18 minutes.

Since it is clear that many if not almost all rishonim supported 22.5 minutes, the change to 18 minutes is puzzling. As we demonstrated, a basic mathematical/logical error allowed many to misread the opinion of all chachmai sforad as not necessarily supporting 22.5 minutes. That error and the limited availability of many of their writings are certainly major contributors for the dominance of 18 minutes as the time to walk a mil. However, I suspect that this might also be an example of the impact on halakhic reasoning from the increasing availability of clocks beginning in the 15th century. Clocks made 90 minutes as the time that three stars appear untenable in central and southern Europe; as a result, perhaps, opinion shifted to a somewhat more reasonable 72 minutes and the associated time to walk a mil of 18 minutes. Prior to the widespread use of clocks, it is likely that observation of the skies, as opposed to either 72 or 90 minutes, was used to determine the end of Shabbat.

2. How long is the period from sunset to tzait (kol) hakochavim (or equivalently alot hashachar to sunrise) in the Middle East around the time of the equinox? – 72 minutes, 90 minutes, 96 minutes, 120 minutes, etc.

96 minutes, four intervals of 24 minutes, referenced in a number of tshuvot, is unsupportable since whoever would maintain a time to walk a mil of 24 minutes must also consider the period from alot hashachar to sunrise as the time to walk 5 and not 4 mil. 120 minutes, while theoretically possible, is rarely encountered in halakha and is inconsistent with the point at which total darkness occurs in the Middle East, approximately 80 minutes after sunset. While both 72 and 90 minutes intervals are good approximations to 80 minutes, I maintain a slight preference for 72 minutes for four reasons: (How adherents of Rabbeinu Tam’s approach reconciled the difference in the length of the interval between dawn and sunrise versus sunset and three stars is unclear. The former would suggest 90 minutes in Europe, the opinion of many later rishonim who lived there. On the other hand, the latter would support 72 minutes. I suspect that given the subjective nature of determining what constitutes the first light and the additional stringencies of three small, adjacent stars, the difference may have become less evident. With the advent of clocks, 72 minutes was perhaps easier to assume if one number had to be chosen for both. This in turn may have made observation yet less authoritative.)

1. The amount of light present at 72 minutes is so minimal that it was likely disregarded in halakha.
2. R. Saadyah Gaon and Rambam, who both lived in the Middle East, support 72 minutes.
3. The simple meaning of 1/10th of the (720 minute) day is 72 minutes; assuming 1/10th to mean 90/900 requires a unique variant of the notion of milebar adding two intervals of 90 minutes to 720.
4. Around the winter solstice in Jerusalem, using an adjusted (or even fixed) 90 minutes in calculating according to the Magen Avraham, results in plag haminkha after sunset. In the winter, when the daytime period is approximately 10 hours and the sun is 20 degrees below the horizon about 96 minutes after sunset, plag haminkha (1.25*66 ~ 83 minutes) occurs approximately 13 minutes after sunset.

3. How is the period from alot hashachar to sunrise or its equivalent from sunset to tzait (kol) hakochavim to be adjusted at different locations and during different seasons (if at all)?

Prior to the widespread use of clocks, latitude and season (and perhaps even altitude) based adjustments were made naturally. The invention of clocks and the subsequent growth of time based expressions of halakha reduced the dependence on observation as have been documented by Prof. Stern.( Time and Process in Ancient Judaism. )

Many calendars exhibit inconsistent behavior, defining misheyakir, for example, based on physical observation, while maintaining an unadjusted period for alot hashachar, a position that creates anomalies at most European latitudes.

In practical terms, the end of a day of the week, when defined either by a measure of darkness or the more common appearance of three stars naturally embed both latitude and seasonal adjustments. However, except for a few isolated exceptions, those who wait 72 minutes after sunset for the end of Shabbat never made upward adjustments. (To my knowledge, no major figure except R. Soloveitchik (and perhaps some family members) applied and practiced precise latitude and seasonal adjustments to lengthen the end of Shabbat when following the opinion of Rabbeinu Tam.) By waiting 72 minutes, they would naturally wait longer than those watching for darkness or the appearance of stars at least until the point that one is approximately 50 degrees latitude or greater from the equator, regardless of the time of year. At latitudes below 50 degrees, even a depression angle of 8.5 degrees, that exceeds the observance of (almost) all communities, would equate to less than 72 minutes. As a result, 72 minutes after sunset remained invariant. Given the location of the vast majority of Jewish communities between 55 degrees north latitude and the equator, those who observed 72 minutes had limited physical motivation to make either latitude or seasonal adjustments; three stars, most often even small ones, are visible by that time. (To the contrary, not just were intervals not adjusted upwards, those who maintained the position of Rabbeinu Tam, either waited exactly 72 minutes or less, not more. As noted previously and first mentioned explicitly by R. Avraham Pimential in the 17th century sefer Minkhat Kohen and practiced in many communities, those following the opinion of Rabbeinu Tam actually reduced 72 minutes (often to around 50 minutes) based on the observation of three stars. I have never read an explanation of how this was reconciled with the calculation for the time of alot hashachar for those following the Rabbeinu Tam. A more traditional view of the Rabbeinu Tam’s position was to wait until 72 minutes after sunset.) (Even for St. Petersburg and certain communities in Scandinavia, given significant variance in how to interpret three small stars, smaller depression angles (but still greater than that which would equate to three medium stars) would allow 72 minutes to remain viable. See Benish chapter 46 on European observance in a number of (very) northern European communities that used the equivalent of a depression angle of approximately 7.5 degrees for the end of Shabbat. In Vilna for example, using a depression angle of 8.5 degrees, the end of Shabbat occurs approximately 95 minutes after sunset in the summer, 40 minutes later than in the spring.)

On the other hand, unlike the end of Shabbat (or any day of the week,) the beginning of the daytime period, alot hashachar, should not have been left invariant, as was often the case. In Prague in June, for example, using a depression angle of 8.5 degrees, the end of Shabbat occurs about 70 minutes after sunset, while alot hashachar, specified by a depression angle of 16 degrees, occurs over three hours before sunrise. However, as it was often axiomatically assumed based on Rabbeinu Tam’s interpretation of the sugya in Pesachim, that the interval between alot hashachar and sunrise must exactly equal the interval between sunset and tzait hakochavim, either both or neither could be adjusted. Particularly in the age of clocks, adjusting one and not the other would visibly violate that assumption. Thus, I suspect that the opinion of Rabbeinu Tam may have contributed to a tradition of not adjusting the time of alot hashachar, in order to maintain similarity with the invariance of the evening zman of a fixed 72 minutes after sunset for tzait hakochavim. The amount of illumination that defines the point of alot hashachar was simply assumed to be greater. (The times for misheyakir may be reflective. The rulings of Middle Eastern poskim tend to equate to depression angles of 11.5 degrees and higher, while European poskim tend to a range between 10 and 11 degrees, as is clear from Benish vol. 1, pages 211 – 215. It is highly likely that a relatively short duration (6 minutes) between alot hashachar and misheyakir that is mentioned by some commentators in OC 58:1 is not the result of an early point of misheyakir but a later point of alot hashachar. As a result, combining such a psak with an accurate (adjusted) time for alot hashachar cannot be justified.)

In summary, three potential impacts of increased reliance on clocks have been suggested in this and preceding sections of the epilogue:

1. Reduced reliance on observation and natural skepticism about of its accuracy, particularly relative to a clock, eventually led to decreased practical knowledge of the meaning of specific physical entities further increasing reliance on clocks. (Arguably alot hashachar, misheyakir, and a medium versus small star have all been impacted .)

2. The clear preference for 72 over 90 minutes as the point at which three (small) stars appear, and the related preference for 18 versus 22.5 minutes as the time to walk a mil.

3. The invariance of the interval from alot hashachar to sunrise resulting from its assumed equivalence to the interval from sunset to tzait hakochavim according to the prevalent opinion of Rabbeinu Tam, created observational challenges. The duration of the interval from sunset to tzait hakochavim rarely exhibits any need for variation by either season or latitudes; the point of alot hashachar clearly does. The use of identical (fixed) intervals for both, weakened reliance on observation and trust in one’s ability to judge levels of darkness.

4. How are we to define the hours of the day – sunrise to sunset or alot hashachar to darkness?

The identification of the opinion of the Magen Avraham only as far back as R. Israel Isserlein as opposed to Ramban (See R. Schechter’s explanation that R. Soloveitchik was completely unconcerned about the opinion of the Magen Avraham because of an implication from Rambam that was a supporting source for the Gaon. It is puzzling that R. Soloveitchik would dismiss an opinion of all chachmai seforad. ) and his school who clearly counted the hours of the day from alot hashachar to darkness remains puzzling. (I assume that this was primarily the result of limited availability of the seforim of chachmai sforad.) Given that the position of the Magen Avraham was held by all chachmai sforad and was the accepted custom of Jerusalem, in spite of the influence of the students of the Gaon, coupled with a lack of any unambiguous reference to the position of the Levushim amongst rishonim, provides additional support to that alternative. The argument of R. Yaffe and the Gaon that time is defined by the angles of the sun, is compelling, but not entirely convincing.

As noted in the past section, current practice, that sets times for the Magen Avraham’s zman based on a fixed 72/90 minutes for both alot hashachar and tzait (kol) hakochavim, is a divergence from zemanim based on observation that was practiced prior to the advent of clocks. For those who wish to maintain the times of the Magen Avraham, their precise approximation / calculation would seem warranted. As hypothesized, the opinion of Rabbeinu Tam and the observance of a fixed 72 (90) minutes at the end of Shabbat might have contributed to a tradition of not adjusting 72 minutes (or 90) minutes in this context as well.

5. Of the three criteria given by the gemara in Shabbat – time, the appearance of stars, darkness (darkening / appearance of the sky / horizon), which if any are the definition of night and which are just approximations or an indication? How can opinions expressed using these three terms be compared?

I maintain a clear bias towards levels of darkness and light defining both the end and the beginning of bein hashemashot, as well as almost all other zemanim. What is not yet fully recognized is that relying on depression angles for defining the level of darkness is akin to relying on clocks to tell time.( I have seen calendars that while using depression angles choose to write three small or medium stars, presumably to make people more comfortable, avoiding marketing challenges and the need to explain.) More importantly, depression angles naturally incorporate adjustments based on season and latitude, something that clocks more than likely obscured. Clocks and even time is just an artifact; depression angles are a mechanism for accurately specifying the halakhic notion of darkness.

While both the appearances of stars and multiple levels of darkness vary naturally with seasons and latitude, clocks likely had impact with their introduction. As time became an easier and preferred method for specifying observance, it is likely that the meaning of darkness levels and the appearance of stars became less observed, relevant or understood.

Motivated by the desire to understand the observations and findings of R. Tukitzinsky more directly, I have carefully observed the appearance of stars and the darkening of the horizon at various latitudes and seasons of the year. As best as I can observe, the point at which the apex of the sky appears as dark as the eastern horizon slightly precedes the appearance of three or more stars. However, it is not yet as dark as the eastern half of the sky will become as one waits longer; the (eastern half of the) sky darkens further until sometime after a point in the evening comparable to the point in the morning of misheyakir. Even at that point, there is still some remaining illumination from the sun visible on the western horizon. Though this level of darkness is in all likelihood what is described in the gemara and has been the psak of generations of poskim for the end of Shabbat, it may well leave one feeling uncertain about the time at which Shabbat ends. Unlike alot hashachar where there is minimal (or no light) light, the end of Shabbat occurs when there is significantly more illumination. Without depression angles that point of chashecha is difficult to specify with precision even relative to three (small, adjacent) stars, perhaps influencing many to view stars as defining.

Assuming that the appearance of three stars and alot hashachar are equidistant from sunrise and sunset also makes it nearly impossible to regard darkness as defining; one would expect it to be equally dark at those two points. Instead, we end Shabbat when there is more illumination than at alot hashachar. This adds yet another reason why some doubted their observation of the degree of darkness, and preferred instead to think both of:

• stars as defining, and
• clocks as more reliable and precise than observation.

6. How is the duration of bein hashemashot to be adjusted at different locations and during different seasons (if at all)? Might this depend on whether bein hashemashot is

1. an interval of uncertainty that is its own unique halakhic category – either

1. a combination of both day and night, or perhaps
2. a category of its own, or

2. an interval with a definitive transition point that we are uncertain how to pinpoint – either

1. practically, or perhaps
2. because of some element of halakhic uncertainty, or

3. an example of the Rabbis establishing a fence?

In this and the following two sections, the approach of the geonim is assumed and options for the length, end, and beginning of bein hashemashot are discussed within their framework. It is easiest to begin with the length of bein hashemashot. This turns out to be a critical method to estimate the beginning of bein hashemashot given the assumption that the end of the bein hashemashot period is not in question. The interval of bein hashemashot can be specified using either of the following constructs:

• the interval between two precisely defined physical events / depression angles, and / or
• an interval of time prior to the end of the day.

Despite the potential dependence of these two constructs on the theoretical alternatives for defining bein hashemashot, I have argued that the issues are independent. The discussion that follows concentrates only on these two alternative constructs; others are either just variations or combinations.

One issue briefly outlined is the difference between safek chashecha and bein hashemashot. I assume that the period of safek chashecha is shorter than bein hashemashot and represents a period of real doubt about whether chashecha and the beginning of Shabbat at a biblical level has occurred. (The remainder of this section could be rewritten independent of this assumed relationship between bein hashemashot and safek chashecha if one were to feel that this assumption is not justified .) Bein hashemashot represents a longer interval, where Shabbat is mandated, but only at a rabbinical level.

The following discussion is not meant to identify a normative position, rather one that presents a preferred, or at least plausible, reading of the gemara and also (partially) justifies the practice of Jewish communities in Europe that started Shabbat well after sunset. Seeking to justify practice even at a rabbinical level requires a relatively short period of bein hashemashot. Using either sunset or even a minimal depression angle would mean that most communities who followed Rabbeinu Tam started Shabbat during bein hashemashot or worse.

Assume, as an illustrative example, that a community ends Shabbat 50 minutes after sunset with the appearance of three small stars. Assume further that while three small stars equate to a depression angle of approximately 8 degrees, three medium stars, the gemara’s end to both bein hashemashot and Shabbat, equates to a depression angle of approximately 6 degrees, and occurs 35 minutes after sunset. Bein hashemashot begins approximately 15 minutes before that, at 20 minutes after sunset. To justify practice, two elements must be considered:

• At the biblical level, the point of chashecha, slightly prior to three medium stars, and
• at a rabbinical level, the interval from the beginning of bein hashemashot until chashecha.

As detailed at the beginning of section 8, three alternative opinions, each to be adjusted by latitude and season advance the beginning of bein hashemashot by 4 to 15 minutes from sunset. At a minimum one would naturally maintain that a level of darkness computed for each of those alternatives must be achieved (to create an element of doubt that is required) to begin bein hashemashot. Additionally, one can maintain that the time to walk 3/4 mil is an absolute upper bound, invariant with respect to latitude and season. Thus, bein hashemashot cannot begin prior to the time to walk ¾ mil before the point of nightfall. If one would want to be as lenient as possible, one would take the later of these two potential times – counting back from chashecha the time to walk ¾ of a mil, while maintaining as well the requirement to reach a particular level of darkness. Thus, bein hashemashot begins at the earliest when a particular level of darkness is reached, (for example, a depression angle of three degrees) but at no time can the interval of bein hashemashot be longer than the time to walk ¾ mil. Using the minimum level of darkness is required slightly north of the latitude of the Middle East and further south approaching the equator. In those locations during certain periods of the year, subtracting the time to walk ¾ of a mil from chashecha might yield time X. However, the time at which a specific level of darkness, which must also occur prior to the start of bein hashemashot, is Y minutes later at time X+Y. For example, assuming that the time to walk ¾ mil is a maximum reached only in the summer, then the bein hashemashot period may begin only within ten minutes of chashekha in the spring and fall when the requisite level of darkness is achieved.

Moving from the Middle East to European latitudes, the focus of this discussion, reaching a particular level of darkness level always occurs at an earlier point than subtracting the time to walk ¾ mil from the point of chashecha. Thus, one obtains the latest (and most lenient) starting point for bein hashemashot by subtracting the time to walk ¾ mil from the point of chashecha, assuming that interval represents an invariant maximum for the period of bein hashemashot. Support for an invariant interval of bein hashemashot came from both R. Lorberbaum and R. Sofer, and in the case of R. Lorberbaum that was coupled with an 18 minute time to walk a mil yielding a period of bein hashemashot of 13.5 minutes. Problematically, in both of those cases the beginning of bein hashemashot was derived subtracting from an end of Shabbat that was determined by the appearance of three small stars. Although their practice was not as stringent as our current practice that equates to a level of darkness associated with a depression angle of 8.5 degrees, it was still one or more degrees greater than the level of darkness associated with a depression angle equating to three medium stars. It appears impossible to justify an overly lenient approach that subtracts from the time that three small stars appear of as opposed to an approach that subtracts from the earlier appearance of three medium stars.

To determine what was the practiced beginning of bein hashemashot requires a detailed historical analysis beyond that begun by Benish. It should be obvious that an early practiced chashecha and a long period of bein hashemashot is likely to avoid both biblical and rabbinic violation on erev Shabbat, while a later practiced chashecha and a short interval of bein hashemashot would create the highest likelihood of even a biblical violation on erev Shabbat. To the extent that the theoretical opinion of the Rabbeinu Tam was used, chillul Shabbat definitely occurred. However, more commonly the opinion of Rabbeinu Tam was equated to three stars with various stringencies, and bein hashemashot began some interval before that. That would make it much more likely that violations that occurred were only at a rabbinic level. Given a large body of evidence including:

• R. Pimentiel’s redefinition of Rabbeinu Tam to the earlier point of three small stars,
• the proposed times of bein hashemashot of both R. Lorberbaum and R. Adler,
• the question concerning the brit of a baby born about 25 minutes after sunset, posed to R. Moshe Sofer,
• the advice from R. Shneur Zalman of Liadi in his Siddur, and
• the natural stringencies that one would expect prior to the existence of clocks.

I doubt any communities (as opposed to individuals) ever started Shabbat as late as the theory of Rabbeinu Tam would have permitted.

While I have scant evidence, one can only assume that any three stars appearing would likely be taken as indicating that the Shabbat had begun. This, together with the halakhic literature only partially referenced above, would all seem to point to a beginning to bein hashemashot, absent tosefet Shabbat, at worse between 30 and 40 minutes after sunset, a point that likely avoided chillul Shabbat at least at the biblical level, particularly in northern European communities. Unfortunately, it is also probable that some individuals started Shabbat even later; the letter of R. Shneur Zalman of Liadi on the beginning of Shabbat, included in all of the Lubavitch movement’s Siddurim, is particularly telling. (R. Shneur Zalman of Liadi suggested that maximal protest be restricted to those who go past approximately a seasonally adjusted 30 minutes, if they refuse to listen initially.)

7. When does the period of bein hashemashot end? How are the criteria specifying the end of the bein hashemashot period interpreted by various authorities?

Of course we assume latitude and season adjustments. We need to specify two points in time – the degree of darkness associated with the approximate appearance of three medium stars (the time given in the gemara) and the degree of darkness associated with three small, adjacent stars (what is now practiced). The former occurs at a depression angle of approximately 6 degrees, and the latter at about 8 degrees. Clearly, practice has many variants around those two points. Currently, a depression angle of 8.5 degrees suggested by R. Tukitzinsky and supported by R. Belsky’s interpretation of R. Feinstein is widely used.

I suspect some will find excessive the intensity with which the opinion of Rabbeinu Tam was found inconsistent with the combination of observation and the gemara’s description of the end of Shabbat. Many might perhaps prefer giving greater credence to difficult and forced efforts at reconciliation. However, current practice, including that of R. Y. Karelitz, which largely disregards Rabbeinu Tam’s opinion on the end of Shabbat, even for absolute biblical restrictions, encourage the conclusions reached. I do not know of another comparable instance where the uncontested opinion of the Shulchan Aruch was so completely overturned.

8. How does the beginning of bein hashemashot relate to what we call sunset? What alternatives might be considered for the beginning of bein hashemashot?

This most controversial topic, moving the beginning of bein hashemashot forward from sunset even according to Rabbah, a variant of the generally assumed opinion of the geonim, successively solves the following issues:

1. at 4 – 5 minutes, the minimal time reported as the custom of Jerusalem (See Minhagei Eretz Yisrael by R. Yaakov Gliss, pages 102 and 282.) as well as the opinion of R. Shneur Zalman of Liadi, the point when the sun disappears from the highest elevations around Jerusalem, Shmuel is consistent at least in a limited sense with R. Yosef but completely inconsistent with Rabbah.

2. at 6 minutes, the opinion of R. Chaim Volozhiner and the appearance of a single star in the spring to an expert observer, Shmuel is more easily consistent with R. Yosef but only consistent in a limited sense with Rabbah.

3. at 7 – 15 minutes depending on a variety of factors, Shmuel becomes entirely consistent with Rabi Yehudah and the time to walk ¾ mil can be considered a practical upper bound. (See Zemanim Kehilkhatam by R. Boorstyn, chapter 2, section 3 where he summarizes different 19th and 20th century poskim in Middle East who supported times beyond 4 – 5 minutes and up to approximately 10 minutes after sunset. The rationale he and some of these poskim used is different from that addressed in this monograph, with heavy reliance on the notion of sea-level in addition to visibility from higher elevations. 15 minutes is the opinion of Rambam according to R. Kapach.)

As stated in the preamble to this monograph, sunset is the established time to start the Shabbat. Where there is a need for greater precision in various circumstances, a posek might consider a construct similar to that provided by R. Nosson Adler. Perhaps a posek can choose to adjust by season and latitude what equates to some point between 4 – 6 and 9 – 12 minutes after sunset in the Middle East around the spring and fall equinox, applying whatever resulting time is the greater chumrah in a d’oraysa and the greater kula in a d’rabbanan. (For a host of reasons, if forced to a single number, I would guess (11 or) 12 minutes. The numbers chosen are purely illustrative.) In cases of (extreme) need, one might also consider limiting the length of the bein hashemashot period to at most 13.5 minutes prior to the appearance of three medium stars, a depression angle of approximately 6 degrees. This area has significant halakhic ramification. (Even if one were to insist on bein hashemashot beginning precisely at sunset, the above zemanim might at least be considered as alternatives for defining the start of safek chashecha.)

Rabbeinu Tam’s late start to Shabbat is yet more troublesome if prior to its formulation, the start of Shabbat was precisely at or even before sunset. I find it highly implausible to imagine Rabbeinu Tam proposing, even as a purely conceptual position, a notion so fundamentally at variance with practice! Even if the practice was to start Shabbat at or before sunset, it would make more sense that the period was only considered a non-mandated interval of tosefet Shabbat. Emergencies that occurred would have clarified the nature of practice. This would lend support to my conclusion: sunset was viewed at most as a non-obligatory start to (tosefet) Shabbat. As Jews migrated to Northern Europe, Shabbat started to separate further from sunset; most likely the start of Shabbat remained at least 15 minutes prior to the appearance of three medium stars. It is for that practice that Rabbeinu Tam provided a conceptual framework. Increased reliance on clocks centuries later, may well have resulted in a (slightly) later start to Shabbat for two reasons. First, the opinion of Rabbeinu Tam could be formulated more precisely. Second, a clock reduced the period of uncertainty that observation of nature naturally introduced.

9. At what time (or within what interval) does one day end and the next day begin with respect to various halakhot? How do the two meanings of day – day as in “day of the week” and day as in “during the daytime” relate? Must the end of the daytime period coincide with the end of a day of the week?

It would be surprising if the different meanings of the term day in both Hebrew and English had no halakhic consequence. On the other hand, one might view this whole category as a modern innovation due to Brisker conceptualization and in opposition to the Gaon finding no halakhic significance to tzait kol hakochavim.

This is the second of a sequence of posts (the first post can be found here), from a draft of a forthcoming monograph by Dr. William Gewirtz that addresses the period of bein hashemashot.  Each post briefly summarizes about 20 pages of the monograph and contains 4 – 6 critical pages from that section as well.   The monograph addresses the period of bein hashemashot, the most fundamental area of dispute in the area of zemanim.  What is proposed is an astronomically accurate hybrid position between the diametrically opposed conceptual views of the geonim and Rabbeinu Tam.  That position justifies, to varying degrees, the practice of countless generations of European Jewry that started Shabbat well after sunset on Friday evening.  Though often ignored in modern times, practical equivalents of this hybrid position have had major adherents throughout the generations.  Furthermore, our goal is to demonstrate that such a position is not just plausible, but in fact the preferred reading of the primary text of the gemara in Shabbat concerning bein hashemashot. This second section

• Introduces the major sugyot on bein hashemashot,
• Lists the topics to be covered in the remainder of the monograph,
• Explicitly specifies some halakhic assumptions, and
• Provides basic background on some relevant astronomy.

The part of this section posted below contains a discussion of the major sugyot concentrating on how Rabbeinu Tam and the geonim differentiate between the sugyot and a fuller discussion of the sugya in Shabbat.   A complete pdf both for this section as well as a pdf for the entire monograph until this point is attached. The primary sugyot – Shabbat 34b and Pesachim 94a and their interrelationship; the basic opinions of the geonim and Rabbeinu Tam and the some of the fundamental challenges each position must address. The gemara in Pesachim discusses whether the period between alot hashachar and sunrise (and the equivalent period from sunset to tzait hakochavim) is the time to walk 4 or 5 mil.[1]  The gemara in Shabbat describes the period of bein hashemashot in a variety of ways to be analyzed below, but when measured in time, sets the interval at either the time to walk ⅔ or ¾ of a mil.  Although it is the tanna Rabi[2] Yehudah’s opinion quoted in both sugyot,[3] the contradiction could be resolved, as some have suggested, by assuming that perhaps Rabi Yehudah changed positions.  However, given the significant discrepancy, almost all commentators attempt to resolve the inconsistency by postulating that the two sugyot are addressing differing intervals. To ground this introduction, assume that the interval between alot hashachar and sunrise is the time to walk four mil and that the time to walk each mil is 18 minutes.[4]  On a canonical day, around the spring and fall equinox, sunrise and sunset are at 6AM and 6PM respectively.  Under these assumptions, according to the gemara in Pesachim, alot hashachar is 4*18 or 72 minutes before sunrise at 4:48AM and tzait hakochavim is 72 minutes after sunset, at 7:12PM.[5]   The conceptual approach of Rabbeinu Tam posits that the endpoints of the sugyot in Shabbat34b and Pesachim 94a are identical.  The end of Shabbat, at the end of the bein hashemashot period in masekhet Shabbat, is at 7:12PM, 72 minutes after sunset.  However, the beginnings of the periods differ between the sugyot.  The gemara in Shabbat refers not to sunset, as we commonly refer to it, but a secondary sunset that occurs later, not just when the sun is no longer visible but rather when almost all of its light is longer visible as well.  That occurs at 6:58 and 30 seconds, almost an hour after what we colloquially call sunset and at that time bein hashemashot begins.  Until that time, the day continues, and on Friday night, work is permitted. The geonim take exactly the opposite position.  In their formulation, the beginning points of the two sugyot are (almost and according to many commentators exactly) identical.  Thus, the period of bein hashemashot begins at sunset.  Shortly thereafter, at 6:13 and 30 seconds, Shabbat ends on Saturday night and work is again permitted.  At 7:12PM, after the full 4 mil period of the sugya in Pesachim, all the stars appear,[6] not just the three medium stars that signify the end of Shabbat. Practice has at various times and for a variety of reasons somewhat softened both positions.  Nevertheless, it is critical to recognize that the disagreement is significant.  In many European communities, Jews who followed Rabbeinu Tam worked well after what we refer to as sunset on Friday evening; many Jews living in Israel and points closer to the equator followed the geonim and ended Shabbat within 30 minutes after sunset.  At least in terms of halakhic theory, a period of approximately an hour, defining both the beginning and end of Shabbat, is in dispute. The approach of the geonim separates the tzait hakochavim discussed in masekhet Shabbat, approximately the time at which three stars appear, from the tzait hakochavim of masekhet Pesachim, the time that all the stars appear.  It is therefore intuitively obvious why the period from alot hashachar to sunrise is identical in length to the period from sunset and the appearance of all the stars.  All the stars appear when no remaining light from the sun impair their visibility; equivalently alot hashachar is coincident with the first rays of light in the morning.  In the morning, as more light from the sun becomes visible, the number of stars that remain visible decreases; in the evening, the reverse occurs and as illumination from the sun disappears completely, all the stars (that can possibly be seen) become visible.  An equal length of time between sunset and when light (however defined) disappears and again between the time light reappears and sunrise is the consequence of this symmetric definition.  However, the approach of Rabbeinu Tam, that equates the tzait hakochavim of masekhet Shabbat and the tzait hakochavim of masekhet Pesachim, must deal with this issue of asymmetry.  How can one equate v        the length of time between alot hashachar, when (almost) all of the stars are still visible and sunrise, withv        the length of time from sunset to the appearance of only three stars?[7] While the approaches of the geonim and Rabbeinu Tam are cited almost exclusively, it is critical to realize that other points of view are possible.  The gemara in Pesachim defines a longer interval of 72 minutes.  As normally assumed, the very short interval of approximately a quarter of an hour that is defined by the gemara in Shabbat is mapped by the geonim to the beginning of the 72 minute interval, while according to Rabbeinu Tam, it maps to the end of the 72 minute interval.  However, at least conceptually, the interval in masekhet Shabbat may begin somewhere between the points suggested by the geonim and Rabbeinu Tam, beginning after sunset at 6:00PM but before 6:58PM and 30 seconds.[8] We raise this, not just as a theoretical possibility.  Rather, as will  become evident, the strongest arguments that have been adduced in favor of the position of Rabbeinu Tam within the classical literature as well as those to be developed in this monograph, imply that the day continues after sunset delaying the start to the bein hashemashot period until sometime after sunset.  Conversely, the greatest challenges to the opinion of Rabbeinu Tam result from his position that the end to the bein hashemashot period extends as late as the time to walk 4 mil after sunset.  First, this requires that the astronomic conditions described in masekhet Shabbat defining the end of bein hashemashot are observable at the time it takes to walk four mil after sunset.  Second, those conditions must be parallel to conditions that exist around alot hashachar.  Neither is apparently true. Therefore, for purpose of analysis, we will separate the argument between the geonim and Rabbeinu Tam into two parts: v        When does the period of bein hashemashot begin?v        When does the period of bein hashemashot end? The length of the period (in the Middle East) is, according to all opinions, (perhaps as most currently assume only around the spring equinox) the time to walk ⅔ or ¾ of a mil. The text of the gemara in Shabbat contains three sections that must be analyzed carefully. Unlike Rabi Yosi, who considers bein hashemashot as occurring instantaneously, during the blink of an eye, Rabi Yehudah, in a statement that the gemara rules as normative for the beginning of Shabbat, defines an interval of bein hashemashot in terms of the appearance of the horizon.  Rabi Yehudah’s precise wording is challenged by the gemara as being inconsistent.  It contains three initial phrases: v        one referring to the setting sun,v        one referring to the sun’s illumination andv        one referring to the darkening horizon and then a fourth phrase that defines the end of the bein hashemashot period.  Rabbah, who approximates the interval of bein hashemashot as the time required to walk ¾ of a mil, assumes all three initial phrases apply to the bein hashemashot interval.  The difficulty with this approach is the repetitive nature of the description, requiring Rabbah to explain that the phrases refer to the beginning and two intermediate points within the bein hashemashot interval.  The need for describing two intermediate points is somewhat forced.[9]  On the other hand, R. Yosef adds a word – “daytime” – and he explains the initial phrases describe an interval after sunset that is still daytime, the second phrase describes the appearance of the (western) horizon just prior to the beginning of bein hashemashot and the third phrase describes a point during bein hashemashot.  The difficulty with this approach is that the word “daytime” has to be added and must be assumed to be understood implicitly in the original formulation of Rabi Yehudah.  This slightly shorter interval for bein hashemashot aligns with R. Yosef’s position that maintains the length of the interval is the time to walk only ⅔ of a mil interval, 1/12 of a mil shorter than Rabbah’s ¾ of a mil interval. The gemara then records a discussion between Abaye and Ravah debating whether one should be looking at the western or eastern horizon; this passage is critical and must be explained according to the interpretations of both the geonim and Rabbeinu Tam.[10] Both Rabbah and R. Yosef attribute their opinion of the position of the tanna Rabi Yehudah to the opinion of the amora R. Yehudah in the name of Shmuel.  Later, the gemara, without any suggestion of disagreement, quotes another statement of R. Yehudah in the name of Shmuel concerning 1, 2 and 3 stars.  We address alternative interpretations of this statement and its relationship to the remainder of the sugya in a subsequent section.[11]   With respect to the argument of Rabbeinu Tam and the geonim, a number of other sugyot are referenced in support of the geonim.  One that is representative is the gemara in Zevachim that asserts that (sacrificial) blood is disqualified at sunset, seemingly in opposition to the opinion of Rabbeinu Tam.[12]  In such instances, one of two arguments can be invoked: v        The halakha that specifies precisely sunset only applies to a unique situation, as in this case of korbanot.v        The language is less clear than one might assume, and sunset refers not its precise astronomical definition but to some later point later when the sun’s impact is diminished. As these sugyot have been extensively quoted and debated,[13] it is unnecessary, except on rare occasion, to review them in this monograph.  Instead, we concentrate on analysis of the basic sugyot mentioned.  One additional source that bears on these two sugyot is the lengthy discussion in the yerushalmi in Berachot 2b[14] that considers the verse in Nehemiah 4:15: v     Veanachnu osim bemelacha…..mei alot hashachar ad tzait hakochavim as defining the daytime period from alot hashachar until the appearance of three stars.  Rabbeinu Tam is entirely consistent with this approach; in fact, it provides an explicit sugya that links the appearance of three stars in the evening as the endpoint corresponding to alot hashachar in the morning.  How the asymmetry is to be dealt with is very different, however, from the overall problem of asymmetry that Rabbeinu Tam must address.  Unlike the gemara in Pesachim, nothing in the yerushalmi, and the other texts that quote the verse in Nehemiah, (even remotely) implies symmetry.  Those sugyot that quote the verse in Nehemiah appear to support a definition of the daytime period that is asymmetric relative to both chatzot and the time from sunrise/sunset.  While this asymmetry may be surprising, it is not, in and of itself, an issue.   On the other hand, the gemara in Pesachim explicitly introduces symmetry by asserting equal intervals bracketing sunrise and sunset, each of the same duration, the time to walk either 4 or 5 mil.   The opinion of Rabbeinu Tam further extends the symmetry of the gemara in Pesachim by equating the endpoints of the sugyot in Shabbat and Pesachim.   By implication, Rabbeinu Tam equates the endpoint in the yerushalmi as well.  For the geonim, however, this gemara in Shabbat (and the yerushalmi in Berachot) is addressing a different endpoint than the (later endpoint referenced in the) gemara in Pesachim. Two approaches to this later point, tzait kol hakochavim, when all the stars appear are possible.  According to the Gaon,[15] the gemara in Pesachim is theoretical; the evening equivalent of alot hashachar, 4 mil after sunset, when all the stars appear, is ascribed no examples of halakhic significance.  Alternatively, one can assume that the while the appearance of three stars approximates or defines the end of each day of the week, the daytime period extends beyond that point, until all illumination from the sun has disappeared.  That later point may apply to specific areas of halakha, where only the daytime period as opposed to the specific day of the week is relevant, a theoretical possibility addressed in section 9. The geonim must deal with a number of questions.  First, since it is universally acknowledged that the day starts with alot hashachar, should it not correspondingly end at an equivalent point after sunset i.e. tzait (kol) hakochavim?  This question is easily addressed.  Symmetry is required only according to the approach of Rabbeinu Tam; for the geonim, given the two distinct definitions of day, the day of the week versus the daytime period, symmetry need not be expected.[16]  Second,[17] and this question is fundamental, after an interval of the time required to walk ¾ of a mil after sunset, in the Middle East, three  medium stars are barely visible, if at all. Rabbeinu Tam must address a number of fundamental questions.  First, In the Middle East three medium stars appear well before the time required to walk 4 mil after sunset.  Second, the description of the horizon around the end of Shabbat as well as the debate between Abaye and Ravah all appear to support the opinion of the geonim.[18]   Third, and most fundamentally, how could the time of appearance of three stars and the time of alot hashachar be identically separated (as specified by the gemara in Pesachim) from sunset and sunrise respectively?  The analog to three stars becoming visible is not alot hashachar when (almost) all stars are still visible. This question and the debate between Ravah and Abaye in Shabbat, present major challenges to the opinion of Rabbeinu Tam.[19] We return to these two sugyot as we analyze the primary halakhic categories below, attempting to formulate responses to the above questions throughout the monograph.[1] We often will use the phrase the time to walk X mil.  Undoubtedly, a person walking for an entire day will cover fewer mil per hour than one who walks for a shorter period.  That adjustment is not how this system of specifying time periods is defined.  Instead, if one walked 32 mil in a daytime period of 12 hours, the time to walk a single mil is 22.5 minutes, 12*60/32, despite the fact that walking only one mil takes significantly less than 22.5 minutes.  Similarly, the number of mil covered in 90 minutes is 90/720, (1/8) * 32 mil = 4 mil.[2] We use “Rabi” to denote a tanna and “R.” for an amora.[3] It is Rabi Yehudah quoted explicitly in Pesachim specifying that bein hashemashot is 1/10 of a day; in Shabbat there is a dispute between Rabbah and R. Yosef concerning the length of Rabi Yehudah’s bein hashemashot period.[4] Both the length of time to walk a mil and the number of mil in the twilight interval are areas we cover in detail in Sections 2 and 3.  Choosing either 22.5 minutes or the more typical 18 minutes as the time to walk a mil, is not consequential to this introduction.  To demonstrate that, the post chose the more typical 18 minutes, while the pdf chose 22.5.  As a result we also use the more typical 72 (4*18) minutes in the post versus the 90 (4*22.5) minutes that is used for illustration in the attached pdf.[5] A careful reading of Rabbeinu Tam (and other poskim) might align 6PM with the sun beginning to go below the horizon, a few minutes prior to the sun having gone completely below the horizon, which is our usual definition of sunset.  Note that this makes the day at the equinox exactly 12 hour, while chatzot is a few minutes early.  We disregard this and other minute differences.  [6] The potential halakhic consequences, if any, of the appearance all the stars is discussed in section 9.[7] This issue is most fundamental.  As we plan to demonstrate, it is impossible to address the issue fully without radically changing some fundamental element of Rabbeinu Tam’s conceptual opinion and/or how it is practiced.   R. Soloveitchik did exactly that both in (personal) practice and in the theory developed in his yarzeit shiur.  Absent so major a change in Rabbeinu Tam’s approach, attempts to deal with this issue will introduce other complications.  One representative issue is that chatzot, when defined as the midpoint between alot hashachar and the appearance of only three stars, will occur too early – not at the precise point when the sun is directly overhead.   Many, as illustrated by Benish, simply disregard the issue or assume that chatzot need not be precise.  Benish cites many examples of calendars from major Jewish communities, ostensibly endorsed by their rabbinic leaders would often calculate chatzot assuming the appearance of three stars and dawn are symmetric endpoints.  There are reasonable options to address this issue; most often, however, the issue was not addressed adequately.  In a somewhat similar fashion, R. Feinstein’s tshuva allowing early morning prayers 90 minutes before sunrise (Igrot Moshe OC  4: 6) and his tshuva on nighttime zemanim (Igrot Moshe OC  4:62,) are not cross-referenced.  This basic issue is addressed in multiple contexts in this monograph.[8] Alternatively, at 7:13PM and 7.5 seconds, if the interval is 90 minutes ending at 7: 30PM.  We do not deal with the isolated opinion of the R. Eliezer miMitz, the author of the Yeraim that posits that the interval in masekhet Shabbat begins approximately 15 minutes before sunset.[9] Perhaps, as is subsequently debated by Ravah and Abaye, the two intermediate points are separately describing conditions in the eastern and western sky.[10] This debate between Abaye and Ravah is covered in section 7.[11] This statement is analyzed carefully in Section 5.[12] Tosfot’s answers in Zevachim 56a s.v. menayin ledam and the discussion in Minkhat Kohen, ma’amar rishon chapters 4, 10, 11, 12 and 14 are prototypical.[13] Minkhat Kohen organizes and comprehensively covers the major sugyot on this issue.[14] Discussion of the verse occurs in more abridged form in the bavli as well – Megillah 20a and Berachot 2b.[15] OC 261.[16] R. Soloveitchik in his yartzeit shiur previously referenced, developed and advanced an argument that clearly affirmed this type of symmetry as he reformulated the opinion of Rabbeinu Tam.  However, as will be discussed, the way Rabbeinu Tam was practiced, did not always comply with this principle of symmetry.[17] It is somewhat surprising that this question was not broadly discussed until the 20th century.   Perhaps, consistent with our central thesis, the Sabbath did not begin precisely at sunset as most now assume, even according to the geonim.[18] This is covered in more detail in section 7.  [19] As will be discussed further in detail, only approaches like those of R. Soloveitchik fully tackle the fundamental questions raised by symmetry with respect to Rabbeinu Tam’s position.