The Jewish fall harvest festival begins on the fifth day after Yom Kippur. It's a radical shift for the Jewish people, going from a solemn and reverential holiday to such a celebratory one. Sukkot is the last of the three pilgrimage festivals, after Passover and Shavu'ot. According to the Bible, the children of Israel wandered the desert for 40 years. Sukkot pays tribute to them, along with celebrating the yearly harvest with the Festival of Ingathering. During Sukkot, the Jewish people are commanded to dwell in a temporary shelter, called a sukkah, in honor of the children of Israel. There are very specific rules that dictate how a sukkah is constructed. As for what "dwell" means, it can be as simple as dining in the shelter, though they're encouraged to spend as much time in the sukkah as possible, including sleeping there if weather permits.