Officially the 10th of the Hebrew month of Nissan (when the Israelites entered the Land), Aliyah Day is celebrated at this time of year – on the 6th or 7th of the Hebrew month of Marcheshvan to coincide with the Torah reading of Lech Lecha, when Abraham was commanded to go to the Land of Israel.
https://www.jpost.com/opinion/article-871928
https://www.jpost.com/opinion/article-871918
https://anglo-list.com/israel-aliyah-day/
https://en.wikipedia.org/wiki/Yom_HaAliyah
https://www.jpost.com/israel-news/article-872014 (celebration at Tel Aviv’s ANU museum)