Celebrated on the 15th of Tishrei, Sukkot commemorates the sukkot (booths) that the Israelites lived in following the Exodus from Egypt; it also celebrates the harvest. Traditionally, Jews build outdoor booths in which they live and eat for seven days. In synagogue, four symbolic species — the palm, a yellow citrus called the etrog, the myrtle, and the willow — are waved in seven directions. Each night, in the sukkah, it is traditional to invite a Biblical figure to be the guest for that night.