2 Kings 23:21

‘Now this day will be a memorial to you, and you shall celebrate it as a feast to Yahweh; throughout your generations you are to celebrate it as a perpetual statute.

Then Josiah celebrated the Passover to Yahweh in Jerusalem, and they slaughtered the Passover animals on the fourteenth day of the first month.

And there had not been celebrated a Passover like it in Israel from the days of Samuel the prophet; nor had any of the kings of Israel celebrated such a Passover as Josiah celebrated with the priests, the Levites, all Judah and Israel who were present, and the inhabitants of Jerusalem.

Josiah Celebrates the Passover