Exodus 12:6

In the fourteenth day of the first month at even is the LORD's passover.

In the fourteenth day of this month, at even, ye shall keep it in his appointed season: according to all the rites of it, and according to all the ceremonies thereof, shall ye keep it.

And in the fourteenth day of the first month is the passover of the LORD.

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. Thou shalt therefore sacrifice the passover unto the LORD thy God, of the flock and the herd, in the place which the LORD shall choose to place his name there. Thou shalt eat no leavened bread with it; seven days shalt thou eat unleavened bread therewith, even the bread of affliction; for thou camest forth out of the land of Egypt in haste: that thou mayest remember the day when thou camest forth out of the land of Egypt all the days of thy life. And there shall be no leavened bread seen with thee in all thy coast seven days; neither shall there any thing of the flesh, which thou sacrificedst the first day at even, remain all night until the morning. Thou mayest not sacrifice the passover within any of thy gates, which the LORD thy God giveth thee: But at the place which the LORD thy God shall choose to place his name in, there thou shalt sacrifice the passover at even, at the going down of the sun, at the season that thou camest forth out of Egypt.

Then they killed the passover on the fourteenth day of the second month: and the priests and the Levites were ashamed, and sanctified themselves, and brought in the burnt offerings into the house of the LORD.

In the first month, in the fourteenth day of the month, ye shall have the passover, a feast of seven days; unleavened bread shall be eaten.