Sukkot is a Biblical holiday that is celebrated for seven days, between 15 and 21 Tishrei.
Sukkot is one of the three pilgrimage holidays mentioned in the Bible, and in the days of the Temple, Jews would go to Jerusalem during Sukkot.
Jews are commanded to live in a sukkah (booth or tabernacle). By doing so, they commemorate the tabernacles of the Israelites in the desert following the exodus from Egypt.
Another commandment associated with the holiday is the gathering of the four species. Gathering the four species means gathering four kinds of plants: a lulav (palm tree frond), an etrog (fruit from a citron tree), three myrtle branches, and two brook willows, which are bound and waved in all directions on each day of the holiday.
