Though a number of views arguing for a precise (longitudinal or shoreline conforming) location for a halakhic dateline, those of the Hazon Ish and Rav Tukatzinsky being most often quoted, have been proposed, this paper argues strongly in favor of a view of major poskim including Rav Tzvi Pesach Frank and Rav Isser Zalman Meltzer that argue that such a line is not defined in halakha. In support of that position, I further argue that the existence of a dateline often thought of as logically necessary, in fact, is not. Rather the halakha is established by local (Jewish) practice as it has evolved. A person leaving such a location while over uninhabited ocean/land maintains previous practice (subject to observations of a new day.)
A related matter not covered, but one to which I hope to return, are the assumptions behind the position of the Hazon Ish, whose position was previously argued by Rav Moshe Lapidus at the end of the 19th century. It drew opposition at that time from Rav Shaul Nathanson, author of the Shoel u’Mashiv.
Though all my articles published on thelehrhaus.com benefit from her meticulous editorial judgment, Davida Kolmar’s work on this article, moving paragraphs, simplifying sentences, etc. made the article clearer and more easily read and understood.