Sukkat is a festival of joy. After Rosh Hashanah - when we ask G-d to forgive our sins by inscribing us in the Book of Life, and after Yom Kippur - when the inscription is sealed, Sukkat is the celebration of G-d's forgiveness (we hope). Hashanah Rabbah is the final day of Sukkat when we receive the final dispensation for the coming year. We say special prayers while holding and waving the lulav and esrog, and we parade around the torah scrolls. There's two more days (in Israel the same day) to celebrate and eat festive meals - Shemini Atzeret and Simchat Torah - and then we settle back to normalcy for a while.