2 Chronicles 35:16-20

So all the service of the LORD was prepared the same day, to keep the passover, and to offer burnt offerings upon the altar of the LORD, according to the commandment of king Josiah.

And the children of Israel that were present kept the passover at that time, and the feast of unleavened bread seven days.

And there was no passover like to that kept in Israel from the days of Samuel the prophet; neither did all the kings of Israel keep such a passover as Josiah kept, and the priests, and the Levites, and all Judah and Israel that were present, and the inhabitants of Jerusalem.

In the eighteenth year of the reign of Josiah was this passover kept.

After all this, when Josiah had prepared the temple, Necho king of Egypt came up to fight against Carchemish by Euphrates: and Josiah went out against him.