Sukkot

Sukkot (Hebrew: סוכות or סֻכּוֹת, sukkōt, or sukkos, Feast of Booths, Feast of Tabernacles) is a Biblical holiday celebrated on the 15th day of the month of Tishrei (late September to late October). It is one of the three (3) biblically-mandated festivals Shalosh regalim on which Jews were commanded to make a pilgrimage to the Temple in Jerusalem. Source http://www.hebcal.com/