Jewish Law
Does the Whole World Share One Shabbat? Halachic Insights on Time Zones, Creation, and the Seventh Day
Why Shabbat doesn’t fall at the same moment worldwide, and what happens when a traveler crosses time zones during the holy day
- Hidabroot Weekend
- |Updated
Because the Earth is spherical, the sun never illuminates the entire world at once. When the sun blazes over Israel, other regions are still wrapped in darkness, and vice versa.
This fact raises a fascinating question, one addressed centuries ago by Rabbi David ben Zimra (the Radbaz): If Shabbat commemorates God’s rest on the seventh day of Creation, shouldn’t the entire world rest simultaneously — just as God ceased His creative work in a single moment?
For example, perhaps all humanity should observe Shabbat according to the times of sunrise and sunset at Marah (where the Israelites were first commanded about Shabbat).
Shabbat Is Personal, Not Global
In Responsa Radbaz (Vol. 1, 76), he explains that this question assumes Shabbat is a universal day of rest for the whole world. But this is a misunderstanding.
Shabbat, he writes, is a covenant between God and Israel, as it says: “It is a sign between Me and you.” (Shemot 31:13)
For this reason, each Jew must keep Shabbat according to the place where they are — maintaining that sacred “sign” in their personal corner of the world.
Every location counts six weekdays and then rests on the seventh. Thus, Shabbat is not one global moment, but a recurring sacred pattern that applies to every person in their own time zone.
Why a Gentile Who Observes Shabbat Is Liable
The Radbaz supports this idea with a striking passage from the Talmud: A non-Jew who observes Shabbat — even on Monday — is liable to death (Sanhedrin 58b).
Why would resting on Monday be considered “keeping Shabbat”?Because Shabbat is defined not by the name of the day, but by the seventh day following six days of work. Thus, if a gentile works six days and rests on the seventh — even if that seventh day happens to fall on our Monday, it is considered a “Shabbat rest,” and therefore forbidden to him.
This demonstrates that the Shabbat cycle is individual, not a single fixed calendar date for all humanity.
The Radbaz also cites the Gemara (Shabbat 69b), which rules that a person lost in the desert who forgets the day of the week should: “Count six days and sanctify the seventh.”
This further illustrates that the concept of Shabbat is personal and cyclical, not globally synchronized.
Creation Unfolded in Time Across the Globe
The Maharit (in Tzafnat Paneach) offers a different but complementary view.
He explains that creation itself did not occur everywhere simultaneously. When God said, “Let the earth bring forth grass”, the process began in one region and spread across the globe over twenty-four hours.
Thus, the creation unfolded in waves, with each part of the world entering its “seventh day” at a slightly different time.
The Chatam Sofer writes similarly: God’s rest on the seventh day also happened region by region, as each area completed its sixth day.
Therefore, Shabbat was given to be observed in each place according to its local seventh day.
(See Responsa “Mishpetei Uziel” Orach Chaim 29, who cites both opinions.)
The Two Approaches
Both the Radbaz and the Maharit–Chatam Sofer agree that every Jew must observe Shabbat according to the seventh day in their current location.
But they differ in their reasoning:
| Approach | Source of Obligation |
|---|---|
| Radbaz | Each Jew is personally commanded to rest one day out of seven. The mitzvah applies to the individual; place only determines when. |
| Maharit & Chatam Sofer | The obligation arises because the seventh day itself has arrived in that place — the holiness of time is bound to geography. |
A Modern Case: Flying from Israel to New York After Havdalah
In modern times, this discussion became practical.
Imagine a Jew in Israel who makes Havdalah on Saturday night — officially ending Shabbat, and then boards a supersonic jet (like the Concorde) and lands in New York, where it is still Saturday afternoon.
What should he do?
He already observed Shabbat that week in Israel.
Yet, he is now in a place where Shabbat is still in force.
The halachic authorities debated this scenario:
According to the Maharit and Chatam Sofer, since the seventh day is still ongoing in his new location, he must keep Shabbat again, for the holiness of time depends on place.
According to the Radbaz, each Jew is obligated to rest only once per week. Since he already fulfilled the mitzvah of Shabbat, he is no longer bound by it — even if he now finds himself where Shabbat is observed.
However, even according to the Radbaz, rabbinically one should act stringently and refrain from melacha (work) while in a place where others are still keeping Shabbat.
This view is echoed by:
The Imrei Emet (Rebbe of Gur, Piskei Teshuvot Vol. 3, 252), who rules that since the mitzvah has been fully fulfilled once, it does not renew.
B’tzel HaChochmah (Vol. 4, 83), who argues that being physically present in a place where it is still Shabbat creates a new obligation from the Torah.
Shabbat is not a universal “moment” of rest that sweeps across the world at once — it is a divinely synchronized rhythm, pulsing through time and space.
Each community, each individual, greets the seventh day according to their horizon — yet all together form a single global symphony of sacred rest.
Thus, whether in Jerusalem or New York, the essence of Shabbat remains the same, as a sign between God and His people — wherever they may be.
