2 Chronicles 30:3
They could not celebrate it at the regular time because not enough priests had performed the ceremonies to make themselves holy and the people had not gathered in Jerusalem.
2 Chronicles 29:34
Since there were not enough priests to kill all these animals, the Levites helped them until the work was finished. By then more priests had made themselves ritually clean. The Levites were more faithful in keeping ritually clean than the priests were.
Exodus 12:6
Take care of it until the fourteenth day of this month. Then at dusk, all the assembled people from the community of Israel must slaughter their animals.
Exodus 12:18
In the first month, on the fourteenth day of the month at evening, you shall eat unleavened bread, until the twenty-first day of the month at evening.
2 Chronicles 29:17
They started on the first day of the first month. On the eighth day they went into Jehovah's entrance hall. For eight days they performed the ceremonies to make Jehovah's Temple holy. They finished on the sixteenth day of the first month.