On April 12, 1951, the Israeli Knesset officially recognized Holocaust Memorial Day. From the article:
"Knesset Passes Resolution for Creating Yom Hashoah (Holocaust Memorial Day) | CIE
Knesset Passes Resolution for Creating Yom Hashoah (Holocaust Memorial Day)
April 12, 1951
A resolution was passed by the Knesset, establishing the 27th day of Nisan as Yom Hashoah (“Holocaust Memorial Day”), a memorial day for the Jews who were victims to the Nazis.
The date was a chosen as a compromise and was proposed by Member of Knesset Rabbi Mordechai Nurok (pictured above), a Holocaust survivor and chair of the committee.
The selection of the 27th of Nisan was made because of its proximity to the date of the Warsaw Ghetto Uprising (the actual date of the uprising was the 14th of Nisan which was not allowed as a memorial day because it was during Passover). This connection, anchoring the day to the Ghetto Uprising, was an example of the reluctance in Israel’s early years to embrace the Holocaust, which was part of the new nation’s collective memory and experience. However, many Israelis preferred to focus on those Jews who engaged in resistance to the Nazis and other perpetrators, not on the Holocaust itself. As a result, the commemoration was originally called Yom Hazikaron la Shoah Ve-Mered Hagetaot (“Holocaust and Ghetto Revolt Memorial Day”).
On April 12th, Nurok addressed the Knesset, “Honorable members of the Knesset, we have seen a graveyard in front of us, a graveyard for six million of our brothers and sisters, and maybe because of their blood, shed like water, we have been privileged to have our state.”
Despite the fact that the resolution was passed in 1951, no formal mandate for commemorating the remembrance day emerged. In August 1953, the Knesset created Yad Vashem as the official Holocaust remembrance authority and tasked it to “promote a custom of joint remembrance of the heroes and victims.” It took until April 1955 for the Knesset to pass a law creating Yom Hashoah (“Holocaust Memorial Day”) and until 1959 to implement the law creating the national holiday."