It is generally taken for granted that only one day of Yom Tov is observed in Israel. However, this may not be entirely true, at least not according to all authorities. It might just be that there are grounds to observe Yom Tov Sheini, a second day of Yom Tov, in Israeli cities that did not exist in Talmudic times. This is true for Israelis as well!
During the Talmudic era, when calendars did not yet exist, the Sanhedrin would sanctify and declare the start of each new lunar month. They would then dispatch messengers to notify Jewish communities nationwide that a new month had begun so that they would be able to prepare for the upcoming holidays accordingly.1
The emissaries of the Sanhedrin would travel up to a ten-day distance from Jerusalem in order to notify even the most isolated communities in the country that a new month had been declared. Those living within this distance of Jerusalem enjoyed a relatively consistent and stable calendar cycle, and as a result, would observe only one day of Yom Tov, just as the Torah requires. However, communities that were situated beyond a ten-day distance were never completely certain when one lunar month had ended and a new one had begun. As such, people living in these places were forced to observe two days of Yom Tov out of uncertainty as to when exactly the upcoming holidays were to be observed.2
Today, when we enjoy the benefit of a fixed calendar, we continue to observe two days of Yom Tov in the Diaspora even though we know exactly when the holidays are to be observed. This is based on the requirement to “follow the customs of our ancestors.”3 It seems, however, that since observing either one or two days of Yom Tov was dependent upon the arrival of the messengers of the Sanhedrin, it stands to reason that any location where these emissaries would not have visited would be required to observe two days of Yom Tov whether in Israel or the Diaspora. This is the view of the Rambam, as we will see.
According to the Rambam, in order for an Israeli city to qualify as a place where only one day of Yom Tov is to be observed, two conditions must be met. First, the city must be situated no further than a ten-day journey from Jerusalem; and second, it must be a city that has been in existence since Talmudic times (or one which lies immediately adjacent to one which has).4 Any city that does not meet both of these conditions must observe Yom Tov Sheini, even today.5
Indeed, it was the practice of a number of Torah sages in Bnei Brak to observe Yom Tov Sheini by not performing any melacha on the second day of Yom Tov and by not eating any chametz on the “eighth” day of Pesach. Although the city of Bnei Brak meets the first condition stated, as it is within a ten-day journey from Jerusalem, it fails to meet the second condition, as Bnei Brak is a new city which did not exist in Talmudic times.6 Rav Yitzchak Zeev Soloveitchik observed two days of Yom Tov when he lived in “new” Jerusalem for similar reasons.
It is interesting to note that some contemporary authorities were so torn on how to rule regarding Yom Tov Sheini in modern-day Israeli cities that they declined to even issue a ruling on the matter!7 The Rambam applies his criteria equally to both Israeli and Diaspora communities. Therefore, according to the Rambam, even Diaspora communities that are situated within a ten-day journey from Jerusalem which would have or could have been visited by the emissaries of the Beit Din, need only observe one day of Yom Tov today as well.8
As one can imagine, the Rambam’s view was almost completely rejected. Most authorities argue that a simpler distinction must be made regarding whether a place should observe one day of Yom Tov or two, and that is by simply differentiating between the Land of Israel and the Diaspora. According to this approach, since most places in Israel were visited by the messengers of the Sanhedrin, it suffices to allow observance of one day of Yom Tov in all areas of Israel. Similarly, since most Diaspora communities were not visited by the messengers of the Sanhedrin, the entire Diaspora must observe two days of Yom Tov.9 In this way, the entire Land of Israel is united in observing one day of Yom Tov and the entire Diaspora is united in observing two days of Yom Tov.
Nevertheless, there are differing views on how those who find themselves in places such as Amman, Beirut, and Damascus for Yom Tov should conduct themselves. Many authorities seem to rule that only one day of Yom Tov need be observed in these places. This is especially true for those who arrived there from Israel and not from another point of origin in the Diaspora. For these, and other reasons, some people keep two days of Yom Tov in Eilat.
1 Rosh Hashana 22b.
2 Rambam, Hilchot Kiddush HaChodesh 5:4,6,12.
3 Rambam, Hilchot Kiddush HaChodesh 5:5.
4 E.g. Beit Shemesh which is situated alongside Tel Beit Shemesh.
5 Rambam, Hilchot Kiddush HaChodesh 5:9-12, Tzitz Eliezer 3:23. See also Piskei Teshuvot 496 footnote 24.
6 Orchot Rabbeinu Vol II p. 113 – 115. See also Piskei Teshuvot 496 footnote 33. Note: According to all accounts, the Bnei Brak of today is not the Bnei Brak which is mentioned in Yehoshua 19:45.
7 Eretz Tzvi 41. Of interest: See Torah Lishma 140 regarding performing melacha on Isru Chag in Israel.
8 Rambam, Hilchot Kiddush HaChodesh 5:9-12.
9 Rosh Hashana 18a, Sukka 43a; Ran, Sukka 22a. See Piskei Teshuvot 496 footnotes 27-32.