II Chronicles 30:21-23

So the children of Israel who were present at Jerusalem kept the Feast of Unleavened Bread seven days with great gladness; and the Levites and the priests praised the LORD day by day, singing to the LORD, accompanied by loud instruments. And Hezekiah gave encouragement to all the Levites who taught the good knowledge of the LORD; and they ate throughout the feast seven days, offering peace offerings and making confession to the LORD God of their fathers. Then the whole assembly agreed to keep the feast another seven days, and they kept it another seven days with gladness.