Answer # 24

Leavened bread may be eaten on the Passover day. But because unleavened bread was used in the actual Passover meal, the day of the Passover came to be considered "the day of unleavened bread" (Luke 22:7). The day of the Passover is a time when all leavened bread is to be put out of the home in preparation for the seven Days of Unleavened Bread (the Feast of Unleavened Bread) that immediately follow (Ex. 12:18-19).

The noted Jewish historian Josephus, who lived in the same century as Christ, tells us that the Feast of Unleavened Bread lasted for seven days - from the 15th day to the 21st day of the first month. The Passover preceded the Feast, being on the 14th day.

However, the entire eight-day Spring Festival was commonly called "The Feast of Unleavened Bread" - that is, from the 14th to the 21st.