Yom HaZikaron
Israel's Memorial Day
From USCJ: Spring Commemoration Resources
May 5, 2014
Yom HaZikaron (יום הזכרון לחללי מערכות ישראל) is the day of remembrance in honor of Israeli veterans and fallen soldiers of the Wars of Israel. The Memorial Day also commemorates fallen civilians, slain by acts of hostile terrorism.
Although Yom HaZikaron is normally observed on the 4th of Iyyar, it may be moved earlier or postponed if observance of the holiday (or Yom HaAtzma'ut, which always follows it) would conflict with Shabbat.