If a person takes a flight from New York to Israel on the night of Tisha B’Ab, such that he arrives in Israel just a few hours before the fast ends there, may he end the fast at nightfall in Israel? Since Israel is seven hours ahead of New York, the traveler in this case will miss seven hours of the fast if he eats when the fast ends in Israel. Is he allowed to end his fast then, or must he wait an additional seven hours, until the fast ends in New York? Must he follow the schedule of the place where he was when the fast began, or does he end the fast at nightfall in his current location?
This issue is subject to debate among the Halachic authorities. Hacham Ovadia Hedaya (Israel, 1889-1969), in his work Yaskil Abdi, ruled that one must fast for twenty-four hours, regardless of where he travels during Tisha B’Ab. Even if one travels to a different time zone, he must wait until nightfall at his city of origin, because the obligation is to fast for twenty-four hours.
Hacham Ovadia Yosef, however, in several places in his writings (Hazon Ovadia – Ta’aniyot; and Yabia Omer, vol. 5, Y.D. 25, in the context of a discussion of Pidyon Ha’ben), disagrees. He claims that a person ends his fast when night falls at his current location, even if he began the fast in a different time zone. Once the stars become visible in one’s current location, he may end the fast, regardless of where he was when Tisha B’Ab began. This is also the ruling of Rav Moshe Feinstein (Russia-New York, 1895-1986), in his Iggerot Moshe (Orah Haim 3:96), and this is the Halacha. Thus, one who travels from New York to Israel on Tisha B’Ab may end the fast when Tisha B’Ab ends in Israel, and does not have to wait an additional seven hours.
Of course, the converse is also true. If a person travels from Israel to New York on Tisha B’Ab, he must continue fasting until nightfall in New York, well after the fast ended in Israel. Even though he began the fast in Israel, he must continue fasting until the stars become visible in his current location.
These Halachot are cited by Rav Pinhas Zebihi, in his work Ateret Paz (p. 271; listen to audio recording for precise citation).
Summary: If a person travels to a different time zone on Tisha B’Ab, he ends the fast when the fast ends in his current location, regardless of whether the fast ends earlier or later in his city of origin.
