The national memorial day for the holocaust in Israel is known as Yom HaShoah and is held on the 27th of Nisan (April/May), unless the 27th would be adjacent to Shabbat, in which case the date is shifted by a day.
The memorial day was inaugurated in 1953, anchored by a law signed by the Prime Minister of Israel David Ben-Gurion and the President of Israel Yitzhak Ben-Zvi.
Most Jewish communities hold a solemn ceremony on this day, but there is no institutionalized ritual observed by all Jews. Lighting memorial candles and reciting the Kaddish—the prayer for the departed—are most common.