February 17 will be the national day of commemoration for Jewish refugees of Arab countries, according to a bill authorized on Sunday by the Ministerial Committee for Legislation.I cannot find direct reference to this decision in the February 17, 1948 meeting of the Arab League. They did decide on "political, military, and economic measures to be taken in response to the Palestine crisis, including withholding petroleum concessions and other possible sanctions against countries aiding the Zionists."
The bill, proposed by MK Shimon Ohayon (Likud Beytenu), states that an official date will be held to honor the 850,000 Jews who were forced out of or fled homes in Arab countries in the mid-20th century.
Ohayon chose February 17 because it was the day in 1948 when the Arab League approved a law for member states to place sanctions against their Jewish population.
The MK also sent a letter to Arab League Secretary-General Dr. Nabil el-Araby Sunday, saying his organization should “accept historic accountability for the humiliation, the suffering and the losses incurred by innocent Jewish victims of the Arab world’s declared war on the State of Israel.”
“As a matter of law and equity, the Arab League must assume full responsibility for ensuring rights and redress for Jewish refugees, the direct result of the collusive actions,” he added. “This is an important element of any future peace and reconciliation between Jews and Arabs in the Middle East.”
However, it does appear that this was when a draft plan to persecute Jews did get realized. This draft plan was written in 1947 and was approved by Egypt, Iraq and Saudi Arabia by January:
The Arabs made no secret that they were threatening Jews in Arab countries during the debates before the UN partition vote in 1947. Heykal Pasha, the Egyptian delegate, said, “The United Nations ... should not lose sight of the fact that the proposed solution might endanger a million Jews living in the Moslem countries. ... If the United Nations decided to partition Palestine they might be responsible for very grave disorders and for the massacre of a large number of Jews.”
It is clear that this was a coordinated effort by Arab countries, using the excuse that it would be a popular uprising against local Jews.
In the end, 99.5% of Jews were ethnically cleansed from their homes in Arab states.
Lots more information in this publication by Justice for Jews in Arab Countries.
(h/t Rudi)