In many years, there is confusion about the proper dates for observing Yom Hashoa, Yom Ha’atzmaut, and Yom Yerushalayim is the Diaspora. After discussions and consultation with our Av Beit Din, Rav Gedalia Dov Schwartz, the position of the RCA is that Diaspora Jewry should celebrate and observe these days on the dates the Chief Rabbinate of Israel designates for them. The Chief Rabbinate publishes these dates on its website.
For 5771/2011, the corresponding dates are
Yom Hashoa should be observed on Monday, Nisan 28/May 2;
Yom Ha’atzmaut on Tuesday, 6 Iyar/May 10; and,
Yom Yerushalayim on Wednesday, 28 Iyar/June 1.