Tu B'Shevat is a holiday also known as the New Year for Trees. The holiday of Tu B’Shevat calculates the age of trees for tithing. The Bible states that fruit from trees may not be eaten during the first three years; the fourth year's fruit is for God, and after that, the fruit can be eaten. Each tree is considered to have aged one year as of Tu B'Shevat. There are few customs or observances related to this holiday. One custom is to eat a new fruit on this day. Some people plant trees on this day. Many Jewish children collect money to plant trees in Israel at this time of year.
Tisha B'Av, literally meaning “the ninth of Av," is a day of mourning to commemorate the destruction of the first and second Temples. Both Temples were destroyed on the ninth of Av, the first by the Babylonians in 586 B.C.E., and the second by the Romans in 70 C.E. Other tragedies that have befallen the Jewish people, many of which coincidentally have occurred on the ninth of Av, are remembered as well. Tisha B'Av usually occurs during August.
A few additional holidays have been added to the calendar to commemorate various significant events relating to the Holocaust and the modern state of Israel. These occur in the period between Passover and Shavuot. These observances reflect the ongoing attempt to mark modern events with the same sanctity of ancient events.
Yom HaShoah also known as Holocaust Remembrance Day, this holiday occurs on the 27th day of Nisan. “Shoah” is the Hebrew word for the Holocaust. This is a Memorial Day for those who died in the Holocaust. Yom HaShoah was inaugurated in 1959, anchored in a law signed by the Prime Minister of Israel David Ben-Gurion and the President of Israel Yitzhak Ben-Zvi.The original proposal was to hold Yom Hashoah on the 15th of Nisan, the anniversary of the Warsaw ghetto uprising (April 19, 1943), but this was problematic because the 15th of Nissan is the first day of Pesach. The date was moved to the 27th of Nisan, which is eight days before Yom Ha'atzma'ut, or Israeli Independence Day. Most Jewish communities hold a solemn ceremony on this day, but there is no institutionalized ritual. Lighting memorial candles and reciting the Kaddish (the prayer for the departed) are common.
Yom Ha-Atzmaut is the holiday celebrating Israeli Independence. Yom Ha'atzmaut takes place on the 5th day of Iyar, the anniversary of the day in which Israel independence was proclaimed, when David Ben Gurion publicly read the Proclamation of the establishment of the State of Israel. The corresponding Gregorian date was May 14, 1948. The festival is celebrated on the 5th of Iyar unless that falls on a Friday or Saturday. This is to avoid having the festival either on Shabbat or immediately before it. If this happens it is brought back to the preceding Thursday (3rd/ 4th Iyar).