2 Chronicles 35:17-18 MSG

17 The Israelites celebrated the Passover, also known as the Feast of Unraised Bread, for seven days.
18 The Passover hadn't been celebrated like this since the days of Samuel the prophet. None of the kings had done it. But Josiah, the priests, the Levites, all Judah and Israel who were there that week, plus the citizens of Jerusalem - they did it.