The Festival of Sukkot begins on Tishri 15, the fifth day after Yom Kippur. It is quite a drastic transition, from one of the most solemn holidays in our year to one of the most joyous. Sukkot is so unreservedly joyful that it is commonly referred to in Jewish prayer and literature as Z'man Simchateinu Z'mn Simchateinu (in Hebrew), the Season of our Rejoicing.
Sukkot is the last of the Shalosh R'galim (three pilgrimage festivals). Like Passover and Shavu'ot, Sukkot has a dual significance: historical and agricultural. Historically, Sukkot commemorates the forty-year period during which the children of Israel were wandering in the desert, living in temporary shelters. Agriculturally, Sukkot is a harvest festival and is sometimes referred to as Chag Ha-Asif Chag Ha-Asif (in Hebrew), the Festival of Ingathering.