What is the Rabbi’s opinion on the institution of Yom Hashoa as a day commemorating the Holocaust. Do we need a special day in addition to Tisha B’Av. I realize the siginificance of the date (because of the anniversary of the Warsaw Ghetto Uprising) but is it still appropriate that it is observed during the joyous month of Nisan?

I read Rav Dov Lior who said that even though initially we would rather have a date not on this month, since it was already established and it is a memorial day rather than a mourning day, it should be a day to commemorate for its great importance and significance