2 Chronicles 35:13-17

So they roasted the Passover animals on the fire according to the ordinance, and they boiled the holy things in pots, in kettles, and in pans and carried them quickly to all the lay people.

Afterward they prepared for themselves and for the priests, because the priests, the sons of Aaron, were offering the burnt offerings and the fat until night; so the Levites prepared for themselves and for the priests, the sons of Aaron.

The singers, the sons of Asaph, were also at their positions according to the command of David, Asaph, Heman, and Jeduthun the king’s seer; and the gatekeepers at each gate did not have to leave their service, because their kinsmen the Levites prepared for them.

So all the service of the Lord was prepared on that day to celebrate the Passover, and to offer burnt offerings on the altar of the Lord according to the command of King Josiah.

And the sons of Israel who were present celebrated the Passover at that time, and the Feast of Unleavened Bread for seven days.