שֵׁ֣שֶׁת יָמִים֮ תֵּעָשֶׂ֣ה מְלָאכָה֒ וּבַיּ֣וֹם הַשְּׁבִיעִ֗י שַׁבַּ֤ת שַׁבָּתוֹן֙ מִקְרָא־קֹ֔דֶשׁ כָּל־מְלָאכָ֖ה לֹ֣א תַעֲשׂ֑וּ שַׁבָּ֥ת הִוא֙ לַֽיהוָ֔ה בְּכֹ֖ל מֽוֹשְׁבֹתֵיכֶֽם׃ (פ)
六日要做工，但第七日是完全安息的安息日，是聖會；任何工作你們都不可做。在你們一切的住處，這是歸給永恆者的安息日。
Collected Responsa in Wartime
The problem of the changing hours of the Sabbath for changing longitudes is a very complicated one. It has recently become the subject of earnest debate and serious disagreement when the practical question arose as to when the Sabbath should be observed in Kobe, Japan, by the Jews who were exiled to the Far East a number of years ago. There is, first of all, the basic question, whether the law requires the same days be celebrated as Sabbath everywhere in accordance with the verse of Leviticus: 23:3: "It is a Sabbath unto the Lord in all your dwellings," or whether Jews should accept the civil conventions of the international date line, or other date line, if any.