In the days of Moshiach, will we still celebrate the second day of Yom Tov of the exiles?
The second day of a holiday is observed as a festival only in the Diaspora. In the ancient days, when the calendar was set according to the sighting of the moon, there were communities that lived too far away from Israel to receive word of the new moon in time. Therefore, they were in doubt whether to celebrate the new moon on the 29th or 30th day of the month. Because of this doubt, they celebrated the holiday for two days. As a remembrance of this practice, we continue to celebrate each holiday for two days in the Diaspora, even though the calendar is no longer set according to the moon.
Regarding this practice, the Chasam Sofer writes: “It seems to me that when G-d will expand our borders, may it happen immediately, and all the islands in the Great Sea will become part of the land of Israel… Those locations will still be too distant to find out the news of the new moon in time, so they will continue to celebrate the second day of Yom Tov, not of the diaspora but of the redemption.”
In other words, even after the Geulah, we will continue to celebrate two days of Yom Tov, not only in the Diaspora but even in the outermost edges of the Land of Israel itself.
It is strange, though, to think that with all the advances of modern communication, some places will be “too far” to find out that there is a new moon in Jerusalem. If so, what reason is there for celebrating the second day of the holiday?
The Chasam Sofer explains that the second day of Yom Tov will be kept not because of doubt about the new moon, but “to remind us that we were in exile, and G-d brought us out and redeemed us from all our woes.”
(Chasam Sfer, Orach Chaim, vol. 145. Drashot Chasam Sofer, Vol. 2, p. 272. Torat Menachem, 5751, vol. 1, p. 207)