2 Chronicles 30:1-3

1King Hezekiah now sent word to all Israel and Judah, and he wrote letters of invitation to the people of Ephraim and Manasseh. He asked everyone to come to the Temple of the Lord at Jerusalem to celebrate the Passover of the Lord, the God of Israel.

2The king, his officials, and all the community of Jerusalem decided to celebrate Passover a month later than usual.

3They were unable to celebrate it at the prescribed time because not enough priests could be purified by then, and the people had not yet assembled at Jerusalem.