M. Friedman wrote:
As I understand it, the reason for celebrating Rosh Hashana and other holidays for two days in the Diaspora was that, given the slow pace of communication in days gone by, it was necessary to be certain that the holiday was celebrated on the correct day. But given the instantaneous communications of the present, what is the reason for continuing this practice instead of conforming the celebration to that done in Israel?
Dear M. Friedman,
Your question is not as new as you might think. In fact, it is a question asked by the Talmud!
Originally, the New Month (Rosh Chodesh) was declared monthly by Israel's Torah court. Many people lived far away and didn't hear about it until after the festivals. To ensure that they observed the festival on the correct day, they observed two days. With the progressive dispersal and persecution of the Jewish People, the Sages saw a need for a fixed calendar.
So your question was as valid 1,500 years ago as it is today: Since today we have a fixed calendar, the doubtful status of the second day no longer exists. Why, then, do we keep two-day festivals?
To answer this question, let's visit Shostka, Ukraine in 1939, where 35 Jews live. The nearest synagogue is in Kiev - a day-and-a-half journey by train. The synagogue phone number is not allowed to be listed in the phone book (if you had a phone). Jewish calendars are banned. When is Passover this year?
According to noted 'refusenik' Rabbi Eliyahu Essas, shlita, Jews knew the festival dates via word of mouth and short-wave radio. But it wasn't easy. People often tried to find out the holiday schedule three years in advance.
Forseeing this and worse, the Sages established two-day festivals. Thus they ensured that festivals be kept correctly, even in the face of repressive decrees against Torah observance.
Speaking of the former Soviet Union: A man in Kiev in 1952 gets a letter from Moscow's CSBMV (Central Soviet Bureau of Motor Vehicles). At last, his request to buy a car has been approved.Sources:
Immediately, he calls Kiev's CDLDA (Central Department of Licencing and Distribution of Automobiles) and is given an appointment for Tuesday, October 3, 1963.
"Morning or Afternoon?" he asks.
"Tavahrisch!" laughs the official. "That's ten years from now! What difference is it to you if you come in the morning or the afternoon?"
"Well," says the man, "the plumber's coming in the morning..."
- Tractate Beitza 4b