Contradiction with Numbers 9:2-3
Numbers 9:2-3 instructs that the Passover should be kept at its appointed time, which is the fourteenth day of the first month, contradicting the postponement of the Passover in 2 Chronicles 30:3.
Numbers 9:2-3: Let the children of Israel also keep the passover at his appointed season.
Contradiction with Deuteronomy 16:1
Deuteronomy 16:1 commands to observe the month of Abib and keep the Passover as appointed, contrasting the delay and alteration of the Passover time in 2 Chronicles 30:3.
Deuteronomy 16:1: Observe the month of Abib, and keep the passover unto the LORD thy God: for in the month of Abib the LORD thy God brought thee forth out of Egypt by night.
Contradiction with Exodus 12:18
Exodus 12:18 specifies the date for observing Passover, the fourteenth day of the first month, which contradicts the different timing decided in 2 Chronicles 30:3.
Exodus 12:18: In the first [month], on the fourteenth day of the month at even, ye shall eat unleavened bread, until the one and twentieth day of the month at even.