According to Exodus 12, on which day of the month did Passover begin?

According to Exodus 12, Passover began on the fourteenth day of the month.

Exodus identifies the month of the Exodus as the first month of the Israelite religious calendar. Families selected a lamb on the tenth day and kept it until the fourteenth day, when it was slaughtered at twilight. Its blood was used on the doorposts, and the meal was eaten that night.

The date is closely connected with the seven-day Festival of Unleavened Bread. Exodus says the Israelites were to remove leaven from their homes and eat unleavened bread during the departure period. Later biblical and Jewish calendar traditions continue to associate Passover with the month of Nisan.

The fourteenth day is sometimes confused with the entire week-long festival. In the Exodus instructions, Passover refers especially to the sacrifice and meal on the fourteenth, while Unleavened Bread continues afterward.