I assume you’re referring to the State of Israel’s date of declaration of independence in 1948. This date was on May 14, 1948 when Israel’s first Prime Minister David Ben Gurion declared Israel’s independence. Its Hebrew date that year was the 5th day of the Hebrew month of Iyar. This is the date of observance most years, except when there is a clash with Shabbat.
An additional aspect to this year's celebration is that it is 70 years since the establishment of the State of Israel. Although this number may seem insignificant relevant to the millennia of existence of the Jewish Nation, 70 years of Modern Statehood is nonetheless quite impressive!
In Hebrew, Israel’s Independence Day is called “Yom Ha’atzma’ut”, which means “Day of Independence”. By the way, this date commemorates the independence of our current Jewish State of Israel, but there is another time on the calendar when we celebrate our freedom as a Jewish People. That other time, of course, is Passover, when God took us out from being slaves in Egypt to being a free nation. In our Passover prayers and blessings we refer to Passover as “the time of our freedom” (“zman cheruteinu”).
It is important to note that the observance of Israel’s Memorial Day – officially called “The Israeli Fallen Soldiers and Victims of Terrorism Remembrance Day” – is commemorated on the day immediately preceding Israel’s Independence Day. This juxtaposition is meant to remind Jews everywhere of the price which the country and its people have paid for the right to exist. In Hebrew it is called “Yom Hazikaron L’challalei Tzahal”.
This year — 2018 — the exact Hebrew date will be on Friday, April 20th, and therefore the celebration will take place a day earlier, in order to avoid conflict with Shabbat. This means that Memorial Day will also be one day earlier, on Wednesday, April 18, and Independence Day will take place on Thursday, April 19.
An official ceremony is held every year on Mount Herzl in Jerusalem on the eve which ushers in Israel’s Independence Day. The ceremony includes speeches, special presentations, marching soldiers forming elaborate patterns, such as a Menorah, a Magen David, a number which represents the age of the State of Israel and the lighting of twelve torches — one for each of the Tribes of Israel. Every year a dozen Israeli citizens who made significant social contributions in selected areas are invited to light the torches. The ceremony concludes with fireworks, which are no less beautiful and inspiring than those of the 4th of July.
One of the key celebrations of Israel's Independence Day is the popular annual “Tanach Contest” (Chidon Tanach) for Jewish youth, held in Jerusalem.
