In pre-modern times, it was relatively easy to determine the end of a fast day. The advent of airplane travel, however, has raised a host of questions as to when a fast should end. In this chapter, we shall discuss four common scenarios: traveling east and not crossing the international date line (nightfall arrives earlier), traveling west and not crossing the date line (nightfall arrives later), traveling west and crossing the date line (potentially curtailing the fast by many hours or even avoiding the fast altogether), and traveling east and crossing the date line (possibly encountering the fast day twice).
Traveling East without Crossing the Date Line
The classic responsum that addresses the question of the impact of the changing time zones on halachic matters was authored by the Radbaz (Teshuvot Haradbaz 1:76) in the sixteenth century. The Radbaz writes that the end of Shabbat is determined by the advent of tzeit hakochavim (the appearance of three medium-sized stars) in the specific place that a person finds himself on Shabbat even if Shabbat has not yet ended in the individual's usual place of residence.110See Seforno to Vayikra 23:3, who adopts a similar approach.
A proof to this approach may be derived from the Gemara (Shabbat 118b) that praises those who begin Shabbat in Tiberius and those who end Shabbat in Tzippori (located in the lower Galilee almost at a midpoint between Haifa and Tiberius). Rashi (ad. loc. s.v. MiMachnisei) explains that Tiberius lies on a low altitude, and thus the sun appears to set early there, leading its residents begin Shabbat early. Tzippori, on the other hand, rests on a mountain where the sun appears to set late, and its residents therefore observe Shabbat until quite late.111Tiberius lies 212 meters below sea level, whileTzippori lies between 70 and 100 meters above sea level.
Rav Akiva Eiger (Gilyon HaShas ad. loc.) cites a responsum of the Ri Migash (45), who explains that the praise refers specifically to those who begin Shabbat in Tiberius and walk on Shabbat to Tzippori to complete Shabbat there. The people who begin Shabbat in Tiberius and end it in Tzippori deserve praise because they place themselves in a situation in which they are obligated to observe Shabbat longer.112In general, Halachah encourages us to create situations in which we are obligated to perform a mitzvot. The practice for men to wear a four cornered garment that requires tzitztit stems from this preference; see Menachot 41a and Tosafot Pesachim 113b s.v. VeEin Lo.
This interpretation of the Gemara seems to teach that even if one is a resident of Tzippori but find himself in Tiberius on Friday evening, he must accept Shabbat when it begins in Tiberius even though it has not yet begun in Tzippori. Similarly, a resident of Tiberius who is located in Tzippori must wait until tzeit hakochavim in Tzippori to end Shabbat even though Shabbat already has ended in Tiberius. This seems to be conclusive proof of the assertion of the Radbaz that the beginning and end of Shabbat are determined by one's location on Shabbat and not by his usual place of residence.
Rav Zvi Pesach Frank (Mikraei Kodesh 2:215), however, questions this proof. He suggests that this passage merely proves that one must be strict in cases where Shabbat ends later than it does in one's hometown, as the Gemara mentions only one who travels from Tiberius to Tzippori. The Gemara does not, however, discuss whether a resident of Tzippori visiting Tiberius may end Shabbat earlier than it ends in Tzippori. It is possible, writes Rav Zvi Pesach, that Halachah requires both that Shabbat end in one's location and his residence. Thus, Rav Frank questions the ruling of the Radbaz113See the comments of the Harerei Kodesh ad. loc. and remains unsure whether an American who lands in Israel may count the Omer at a time when it is nightfall in Israel but not yet nightfall in the United States.
Nearly all contemporary poskim, though, accept the Radbaz's ruling in both strict and lenient directions. For example, Dayan Weisz (Teshuvot Minchat Yitzchak 6:84), Rav Wosner (Teshuvot Sheivet HaLevi 2:93 and 6:129:26), Rav Ovadia Yosef (Taharat HaBayit 2:277-280), and Rav Feivel Cohen (Badei HaShulchan 196:1, Beiurim s.v. Shivat Yamim) all rule that a woman who begins counting seven clean days in the United States and subsequently travels to Israel may immerse at nightfall in Israel even though it is not yet nightfall in America.114This is a striking example, since poskim normally are quite strict about the seven clean days (see, for example, Shulchan Aruch Y.D. 196:4 and Gray Matter 2:98-100), yet they rule in accordance with the Radbaz even in a lenient direction.
These authorities rely to a great extent on a ruling of the Teshuvot Chavatzelet HaSharon (1 Y.D. 47), who adopts the approach of the Radbaz in both strict and lenient directions and asserts that it applies to all halachic concerns. To prove his point, the Chavatzelet HaSharon notes the common practice to regard a boy as Bar Mitzvah immediately at tzeit hakochavim on his thirteenth birthday without inquiry as to the location of his birth to determine if it already is tzeit hakochavim in that locale.
Accordingly, it is not surprising that Rav Aharon Felder (Moadei Yeshurun p. 109) cites Rav Moshe Feinstein's ruling (Teshuvot Igrot Moshe O.C. 3:96) that one who travels east may end the fast when it becomes tzeit hakochavim in his location even though his fasting time will be reduced as a result. Rav Hershel Schachter told me that we may follow this ruling of Rav Moshe. We should add that it is not proper to deliberately schedule one's eastbound plane travel for a fast day in order to avoid the obligation to fast.
Traveling West without Crossing the Date Line
Those who travel west on a fast day are faced with the opposite situation. Their fast will be lengthened, as they will encounter nightfall much later than they would have had they remained home. The question is whether westbound travelers must continue their fast until they encounter tzeit hakochavim.
The initial question that must be addressed is the status of the obligation to fast on the 17th of Tammuz, Tzom Gedaliah, and the 10th of Teiveit. If it can be determined that we observe these fasts as minhag (custom) and not rabbinic law, it might possible to justify ending these fasts earlier. Tisha B’Av, though, undoubtedly constitutes a rabbinic obligation, and one must wait until nightfall to end the fast. Chazal are quite strict about Tisha B’Av (see Rosh Hashanah 18b and Taanit 12b), as they even treat it with the severity of Yom Kippur in some instances (see Pesachim 54b).
The primary source for this discussion is the Gemara (Rosh Hashanah 18b) that asks why the three aforementioned days are described in Zechariah (8:19) on one hand as fast days and on the other hand as days that eventually will be times of joy. The Gemara cites Rav Papa, who resolves this contradiction by distinguishing between three different situations.When peace prevails, these days are offset aside for celebration. Rashi explains that this refers to a time when nochrim do not control us. The Gemara continues that if we suffer from government persecution, the three days will are obligatory days of fasting. Rav Yosef Dov Soloveitchik (cited by Rav Hershel Schachter in Nefesh Harav p. 197) related that there were poskim in Europe who ruled that the Holocaust years were times of government persecution and that we were obligated to fast on these three days according to rabbinic law. Rav Schachter clarified to me that this ruling applied only to those suffering directly under Nazi rule and not those who lived in the United States.
The Gemara concludes that in a time when there is neither peace nor government persecution, fasting is optional. The Gemara clarifies, however, that one must fast on Tisha B’Av even if there is no government persecution due to the severity of the tragedies that occurred on that day.
In which circumstance do we live? Although one might argue that after the establishment of Medinat Yisrael, we are not controlled by nochrim anymore, the sad reality is that Israel is highly dependent on the goodwill of other nations, especially the United States. In addition, Jews who do not reside in Israel are under the direct control of nochrim. On the other hand, there do not seem to be government persecutions in our times. It thus seems most appropriate to classify our times as times of neither peace nor government persecution. If so, although the three days in question should not be treated as days of celebration, there is no rabbinic obligation to fast either. However, the Maggid Mishneh (commenting on Rambam Hilchot Taaniot 5:5) notes that "now" (the time of the Rishonim), the common practice is for everyone to fast on these three fasts even though there is no government persecution.115The Maggid Mishneh writes that we must fast on these days until he Beit Hamikdash is rebuilt. This point is codified as normative Halachah by the Shulchan Aruch (O.C. 549:1 and 550:1) and Mishnah Berurah (550:1). As such, even though we are not (in most situations) obligated to fast on these three days, the custom adopted during the time of the Rishonim to fast on these days even when there is no government persecution is accepted and is binding upon us.
The Stockholm Precedent
Rav Yosef Cohen presents a lenient ruling (Harerei Kodesh to Mikraei Kodesh 2 p. 214) for those traveling westward. Rav Cohen cites the precedent of the Jewish community of Stockholm that concluded their fasting on the 17th of Tammuz at 9:30 P.M. even though nightfall arrives much later there. The Nachal Eshkol (commentary to Sefer HaEshkol, Hilchot Tisha B’Av), writing in the nineteenth century, justifies this practice by noting that at the time the Jewish people accepted the practice to fast on the 17th of Tammuz, Tzom Gedaliah and the 10th of Teiveit in all circumstances, no Jewish community extended as far north as Stockholm. Thus, he argues that the original acceptance to fast never applied to fasting later than 9:30 P.M., since no Jewish community at that time observed any of these three fasts later than 9:30 P.M.
Rav Cohen rules that the same can be said for westbound travelers on these three fasts. The original acceptance did not apply to such an extended fast. It is not clear, though, when Rav Cohen would permit a westbound traveler to end his fast. Rabbi David Pahmer (Journal of Halacha and Contemporary Society Spring 1991 p. 78), though, presents this opinion as permitting westbound air travelers to conclude their fast at 9:30 P.M., regardless of when nightfall arrives.
Rav Feinstein and Rav Wosner
Not all authorities agree with this approach. Rav Moshe Feinstein (cited by Rav Aharon Felder, Moadei Yeshurun p. 109; see Teshuvot Igrot Moshe O.C. 3:96) and Da’at Torah (end of ch. 549) rule that westbound travelers must continue their fast until they encounter nightfall. These authorities do not make any special exemptions no matter how long the fasting time is increased. This is not an exceptional ruling, since we explained earlier that a person’s halachic status is determined by his location, not by his residence. Thus, if one is located in an area at a time that is still the 17th of Tammuz, he must continue fasting.
Rav Shmuel Wosner (Teshuvot Sheivet HaLevi 7:76) adopts somewhat of a compromise approach between Rav Cohen and Rav Moshe. He expresses considerable reservations about the Stockholm-precedent and even questions its validity. His basic concern is that there is no source for the Nachal Eshkol’s assertion in the Gemara or Rishonim. Moreover, he reasons that it seems that when the Jewish people accepted the obligation to fast on the aforementioned three fasts, they accepted the obligation to fast in accordance with the rules of fasting. Since the Gemara (Taanit 12a) states that any fast that does not conclude with sundown is not considered a proper fast day, a fast day by definition means fasting until nightfall, regardless of how late that may be.
Accordingly, Rav Wosner reasons, when we accepted the obligation of these three fasts, we accepted the obligation to complete them regardless of how late they may end. Indeed, observant communities in England where tzeit hakochavim is quite late during the summer, end their fast long after 9:30 in the evening. Moreover, Rav Hershel Schachter told me that when he once discussed the practice in Stockholm, a talmid in the shiur whose father served as a Rav in Stockholm mentioned that the Jewish community there no longer ends the fast at 9:30 P.M.
Nonetheless, Rav Wosner allows westbound travelers to conclude their fast at sundown (shkiat hachama) rather than the usual tzeit hakochavim. Rav Wosner notes that the proper time to end a fast already was disputed in the time of the Rishonim.
Although the Shulchan Aruch (O.C. 562:2) rules in accordance with the Rosh (Taanit 1:12) that even the three fasts conclude at Tzeit HaKochavim, other Rishonim (such as Rabbeinu Yonah, cited in the Rosh Shabbat 2:23) believe that they end at sundown. Tosafot (Avodah Zarah 34a s.v. Mitanin) note that the straightforward reading of the aforementioned Gemara (Taanit 12a) indicates that these three fasts end at sundown, but they record that the common practice was (and remains until this day) to conclude even these three fasts at nightfall.
Nonetheless, the Aruch Hashulchan (O.C. 562:9) believes that both the Rambam and the Vilna Gaon (O.C. 562:1 s.v. Ad Tzeit HaKochavim) rule that these three fasts end at shkiah and therefore concludes that a Rav who rules that one may conclude these three fasts at sundown is not to be denegrated. In practice, some rabbanim will rely on these lenient opinions for someone who experiences an unusually difficult fast, while other rabbanim will not rely on these opinions even in case of need, as the Mishnah Berurah does not even cite these lenient opinions. Accordingly, Rav Wosner permits westbound travelers who are experiencing an extraordinarily long fast to rely on the lenient opinion in conjunction with the approach of the Nachal Eshkol.
Moreover, Rav Wosner writes that if one feels that it is too difficult to fast the extended hours to the extent that he feels overwhelmed by the fast, it would be permitted to eat enough to restore his well-being even before sundown. However, Rav Wosner writes that the rules of the taanit remain in effect even for one who ate a bit to restore his well-being (see Shulchan Aruch O.C. 568:1). Citing the Teshuvot Chatam Sofer (O.C. 157), he writes that in such circumstances, one should eat only what is necessary. Rav Wosner does not mention a requirement that one eat less than a shiur at a time as is required on Yom Kippur (see Shulchan Aruch O.C. 618) and, according to some poskim, on Tisha B’Av.116See Gray Matter 3:41-47.
Westbound Travelers who Cross the Date Line
Although most westbound air travelers will find their fasting time extended, some potentially reduce or even avoid the fast altogether by crossing the international date line during the flight. One would avoid the fast if he would begin his travel on the evening of the 17th of Tammuz and would fly west, crossing the date line before dawn of the 18th of Tammuz. In such a case, one will not encounter the time when he is obligated to fast, because as he crosses the date line, he enters the 18th of Tammuz. The question is whether a person in such circumstances is completely excused from observing the fast.
Rav David Pahmer (ad. loc. p.77) writes the following (echoing the views of Rav Hershel Schachter):
Consider someone crossing the dateline from Tuesday, 3 P.M. into Wednesday, 3 P.M…even if he has already davened Mincha, he must daven again because his first Mincha was for his obligation to daven on Tuesday, and he now has an obligation to daven on Wednesday [he must also be sure to recite Minchah for Tuesday before crossing the date line - C.J.]. Similarly, he must put on Tefillin…If he crosses the line during the 49 days of the Omer, he must count for the new day. A woman in the midst of the seven clean days of niddut has just jumped into the next day. 117See Halachos for the Traveler pages 25-26 for a dissenting opinion. Generally, the dateline affects any issue which depends on the calendar day.
This approach hardly is surprising, as nearly all of the contemporary poskim have concluded, based on rulings of the Radbaz and Chavatzelet HaSharon, that one follows the standards of the community in which he finds himself. Indeed, the Encyclopedia Talmudit (22:405; see n. 620 as well as p. 403 n. 608) notes that this approach is endorsed by many Acharonim, including the Chazon Ish and the Teshuvot Eretz Zvi (44).
Accordingly, one is not obligated to fast if he is located in a place where it is not the 17th of Tammuz or the 10th of Teiveit even though it may be a fast day in his place of residence. Thus, one would either avoid the fast altogether or end the fast as soon as he crosses the dateline. Indeed, Rav Hershel Schachter told me that this is his opinion. He remarked that this is analogous to the situation described by the Chazon Ish (O.C. 152) of one who spends the 14th of Adar in Yerushalayim and the 15th in Tel Aviv. The Chazon Ish rules that such a person is not obligated to observe Purim on either day. We should emphasize again that one certainly should not schedule a trip to dodge or limit the obligation to fast (or observe Purim), as noted by Teshuvot Eretz Tzvi (44) in the specific context of crossing the date line.
Not all authorities agree with Rav Schachter. Rav Moshe Heinemann 118His ruling appears at www.star-k.org/kashrus/kk-trav-dateline.htm An essay that appears in Jewish Action (Summer 5767 page 66) states that the approach presented on the Star-K website represents the majority opinion: “There is a disagreement among posekim regarding the obligation of tefillin and prayer. What creates the obligation: the actual calendar day or the daily phenomenon of sunrise? Most posekim maintain the latter”. The article concludes that “if you donned tefillin in the morning and davened Shacharit, and subsequently flew westward into a new day” he should put tefillin on again and say the Shemoneh Esrei again as a tefillat nedavah (voluntary prayer). One should consult his Rav as to whose opinion should be followed. rules that:
Halachos relating specifically to the time of day are not affected by crossing the Dateline. For example, if one davens Shacharis on Monday morning on a plane flying westbound, and crosses the Dateline ’into‘ Tuesday morning, one does not daven Shacharis again. The person has already fulfilled his obligation and is not required to perform these mitzvos until the sun sets and rises again. However, mitzvos that are dependent on the day of the week or month are affected by crossing the Dateline. For example, if one crosses the line westbound from 1:00 p.m. Thursday to 1:00 p.m. Friday, one must begin preparing for Shabbos as it is Erev Shabbos and Shabbos will begin in several hours.
He does agree, accordingly, with Rav Schachter that, “If one flies westbound from 1:00 p.m. on Monday, the 16th of Tammuz, and crosses the halachic Dateline to 1:00 p.m. Tuesday on the 17th of Tammuz, one fasts until nightfall”.
Traveling East and Crossing the Date Line
Conversely, most eastbound air travelers will find their fast curtailed. However, one who has completed a fast of in a community that lies west of the date line, such as Singapore or Hong Kong, and subsequently boards an eastbound flight will again encounter the fast day once he crosses the dateline, as one who crosses to the eastern side of the date line “gains” a day.
We should note that there is a precedent for observing a holiday twice in one year. If one is located in Tel Aviv on the 14th of Adar and in Yerushalayim on the 15th of Adar, the Chazon Ish (O.C. 152) writes that he would be obligated to observe Purim on both days. It seems, though, that those who follow and further apply the reasoning of the Nachal Eshkol’s justification of the practice in Stockholm would rule that we never accepted an obligation to fast twice within a 24-hour period.
Rav Asher Bush (Teshuvot Sho'el BeShlomo 40) addresses this question in the context of Taanit Ester.119Admittedly, this fast is treated more leniently by poskim; see Rama O.C. 686:2 and my essay discussing Taanit Ester available at www.koltorah.org. He cites the Beit Yosef (O.C. 686 s.v. UMah SheKatav), who writes that we do not commemorate Ester's three day fast with three days of fasting "in order not to impose too much of a burden on the community" and criticizes as excessive (ad. loc. s.v. Katuv, citing the Shibolei HaLeket) those who fast Taanit Ester on both Thursday and Friday when Purim falls out on Sunday. Rav Bush considers these to be precedents for not requiring an eastbound traveler to resume a fast when he reenters the 13th of Adar. He argues that we never accepted the custom to fast Ta’anit Ester for two days.
It seems that the same can be said for other fast days that we in current circumstances observe due to custom. Rav Hershel Schachter told me that he agrees with this ruling. Furthermore, the 17th of Tammuz, Tzom Gedaliah, and the 10th of Teiveit are described in Zechariah (8:19) as Tzom HaRevi’i, Tzom HaShevi’i, and Tzom HaAsiri, the fast of the fourth month, the fast of the seventh month, and the fast of the tenth month, respectively. Rav Schachter infers that by definition, there is an obligation (stemming from the pasuk in Zechariah) to fast only once in the fourth month (Tammuz), once in the seventh month (Tishrei), and once in the tenth month (Teiveit).120See Halachos for the Traveler pp. 24-25 for a dissenting view.
The Gerrer Rebbe (in a responsum that appears in Piskei Teshuvah 252, which was published in 5697) discusses one who embarks on Motza’ei Yom Kippur and reenters Yom Kippur in the air. He writes that on a biblical level, one is not obligated to resume fasting. He bases his assertion on the pasuk (Vayikra 23:32) that presents the obligation to fast on Yom Kippur as "meierev ad erev," (from evening to evening). Thus, it seems that one does not observe Yom Kippur unless he was in that location in the evening at the beginning of the fast. The Gerrer Rebbe, though, implies that rabbinic law requires one to resume fasting if he has re-entered Yom Kippur. This does not imply that rabbinic law requires one to fast upon reentering other fast days, since these fasts are not rooted in biblical law and are not treated nearly as strictly as Yom Kippur.
The Teshuvot Eretz Zvi (44) believes that an air traveler does not join Shabbat in progress, since the halachic status of many items is determined by their status at the beginning of Shabbat.121Among other things, this applies to the laws of muktzeh, eiruvei chatzeirot, and eiruvei techumin. Rav Schachter develops this principle at length in chapter seven of his Eretz Hatzvi. Rav Schachter (Eretz HaTzvi p. 67) believes that nonetheless, rabbinic law obligates one who enters Shabbat in progress to observe Shabbat.
These exceptions of not joining Shabbat or Yom Kippur in progress do not seem to apply to all other areas of Halachah; both have unique considerations that preclude entering them in progress. Thus, it would seem that one who is traveling westward on the 16th of Tammuz or the 9th of Teiveit and crosses the date line, he must join the fast in progress. Indeed, Rav Schachter believes that such an individual enters the new day, thereby requiring him to don tefillin and daven Minchah, as noted earlier. Thus, it would seem that he should also begin to fast once he has entered the dateline.
Location of the Halachic Date Line
Although one enters the new day when crossing the dateline, poskim vigorously debate the location of the dateline according to halachic standards.122The Encyclopedia Talmudit (22:398-407) notes no less than thirteen opinions on this subject. Maps outlining the major opinions are included in the aforementioned essays of the Orthodox Union and the Star-K. The three basic opinions are that it lies 90 degrees east of Yerushalayim (Chazon Ish), 180 degrees from Yerushalayim (Rav Yechiel Michal Tukachinsky), or that we may follow the international date line located 180 degrees from Greenwich, England (Rav Zvi Pesach Frank). Rav Hershel Schachter (B’ikvei Hatzon p. 67) is strongly inclined to follow the opinion of the Chazon Ish, while Rav Elazar Meyer Teitz told me that rabbanim of the previous generation regarded the Chazon Ish's view as a minority opinion. Thus, one must consult his Rav for a ruling regarding this matter.
We should also add that Rav Schachter (ad. loc.) rules that the date line for air travelers differs from the date line for those on land. The Chazon Ish rules that the dateline hugs the eastern coastline of those continents through which the halachic dateline passes according to his opinion (i.e. Asia and Australia). He reasons that "ein mechalkin hayabashot," we do not split a continent as partly on one side of the date line and partly on the other. Accordingly, the Chazon Ish regards Sydney and Melbourne (located on the eastern coast of Australia) as being west of the date line even though they are located more than ninety degrees east of Yerushalayim.
Rav Schachter reasons that this logic applies only to one who is located on land, not to one traveling in the air. Thus, according to Rav Schachter, one who embarks on a plane trip from Melbourne or Sydney on Sunday enters Shabbat immediately upon takeoff! One should consult his Rav about this matter. 123The aforementioned essay that appears on the Star-K website does not present this view of Rav Schachter. Fortunately, it is common today for planes to display maps showing where the plane is located, thereby making it easier for one to determine a halachically appropriate course of action.
An Eastbound Plane that Returns Westward
I was told of a situation where a plane that headed east on a fast day encountered nightfall (whereupon the observant Jewish passengers ended their fast) and then, due to engine trouble, needed to return to New York. The passengers were consequently returned to daylight and the date of the fast. The question was whether they were obligated to return to the fast that they had begun. Perhaps one could say also say, similar to the Nachal Eshkol, that we never accepted an obligation to fast in such a situation. Rav Schachter told me that he believes that once the fast has terminated, one is not obligated to begin it again even if one does not accept the Nachal Eshkol's justification of the practice in Stockholm.
Conclusion
Several points emerge from this discussion. Eastbound air travelers who do not cross the date line may end their fast when they encounter nightfall according to nearly all poskim. There is, however, considerable dispute regarding whether westbound air travelers who do not cross the date line must conclude their fast later. Fasts appear to conclude (or begin) when crossing the date line from east to west, but there is considerable dispute regarding the location of the date line as defined by Halachah. According to Rav Hershel Schachter, one who has already observed these three fasts does not return to the fast when crossing the date line from west to east. One should consult his Rav for a ruling regarding the points of dispute.