TSK · Numbers 9:3

You must care for it until the fourteenth day of this month, and then the whole community of Israel will kill it around sundown.

They may observe it on the fourteenth day of the second month at twilight; they are to eat it with bread made without yeast and with bitter herbs.

They slaughtered the Passover lamb on the fourteenth day of the second month. The priests and Levites were ashamed, so they consecrated themselves and brought burnt sacrifices to the LORD’s temple.