R. David Horwitz writes about his trip to Japan with Yeshiva College students and how they handled the issue of whether Shabbos in Japan falls out on Saturday or Sunday, i.e. what side of the halakhic international dateline Japan is on ("Halakhah in the Land of the Rising Sun: Challenges and Strategies" in Chavrusa 42:2 December 2007, pp. 6, 12 - link [PDF]):
At the end of the day, after all the theoretical issues were hashed and rehashed, we had to make a decision how to proceed. In spite of all the difficulties in the Hazon Ish’s position, how could one simply disregard his view? On the other hand, we couldn’t become paralyzed due to the situation! After much consultation with different Rabbanim (including one who was in the Far East with the Mir yeshiva in Japan during World War Two, and told me that many Yeshiva bahurim then and there were hoshesh for the Hazon Ish’s view, but only for dinim de-oraita), I concluded that “Shabbat in Japan will be our Shabbat. On Saturday night and on Sunday we will be mahmir like shitat Hazon Ish (that is, consider it Friday night and Shabbat morning) for dinei de-oraita (only). The determination whether something is de-oraita or derabanan will be according to the consensus of posekim.”
Click here to read moreImplementing these decisions into our actual schedule would serve to be quite an interesting challenge. Our first problem was to find someone who would act as a “Sunday goy.” (Since amira la-Akum on Shabbat is only assur mi-derabanan, he could perform any melakhot de-oraita, and allow us to have a fuller schedule on Sunday.) We were lucky to have Dr. William Lambert Lee, professor of English literature at Yeshiva College, who directed the Schottenstein Honors program at Yeshiva College, accompany us on the trip. He graciously agreed to serve as the “Sunday goy.” Thus, after Ma’ariv on Saturday night, he lit his Zeppo lighter and used it as the “esh” for our havdalah service...
On Sunday I ruled that the Ashkenazic students certainly could carry in any area not designated as Reshut ha-Rabim according to Rashi and the other authorities who follow his view. But our group contained the aforementioned three Sephardic students! They certainly could not disregard the more stringent position le-halakhah of the Bet Yosef. Moreover, the large and noisy shopping district we were now planning to go to on Sunday, although not as famous as the heavily populated Ginza district, by all accounts seemed to be a safeq shishim ribo! (Actually, the dispute between the late R. Moshe Feinstein, zatzal and others about whether one measures shishim ribo as a “point” through which 600,000 people pass through, our as a “box” of 12 mil times 12 mil was germane. I thought we should be mahmir as per R. Moshe’s position, especially as we had Dr. Lee’s kind services in any event.)
Once again, Dr. Lee rode to the rescue. He carried the students’ wallets for the entire duration of time that we were in an area that was safeq reshut ha-rabim. Only after we were safely inside the Japanese equivalent of Bloomingdale’s did we retrieve our wallets. Before we left the store, we gave him our wallets again. (Meqah u-memkar inside the store per se and tiltul muqtzeh, were not problems for us, as those issurim are only miderabanan. We could not sign our signatures for purchases via credit cards ke-derekh ketivah, however.) Dr. Lee even carried articles that we had bought in several large knapsacks that he had prepared for the situation. Returning by subway to the (relatively secluded) area where Azabu Court, our hotel/hostel was located, Dr. Lee announced, “Ashkenazim, you may now retrieve your wallets; Sephardim, I will hold on to them until we get to the actual courtyard of the hotel (a halakhic karmelit)”.