The Bible might not be clear as to the exact date (day, month or year) of Christmas, but it is clear about the date of the Easter story. It is tied in with the story of the Passover; the Passover feast held in Jewish families is set the weekend at the time of the first full moon after the equinox. The history of the Passover goes back to the time of Moses as one of the plagues used to let the people of Israel go from Egypt to the Promised land. Passover comes from the commandment by Moses that they should kill a lamb, splash the blood on their doorposts so the angel of death would then Passover their homes.
The lamb was to be slaughtered with religious ceremony, roasted, and eaten with unleavened bread and bitter herbs in memory of their exodus out of slavery. The eating of unleavened bread was to last seven days to remember the time of their escape when they would not be able to put leaven in their bread during that time to be called the feast of the unleavened bread.
This was an important festival in the time of Jesus among the Israelites to remember how God had set them free from slavery in Egypt. It was celebrated by elaborate ceremony starting the Thursday before sundown on Friday which was the beginning of the Jewish Sabbath. The story of Jesus celebrating the Passover feast with his disciples is told clearly in the gospels. The gospels also emphasize the importance of the death of Jesus happening before sundown on Friday.
They also emphasize the importance of the time element as the women had to wait until sun up on the first day of the week, our Sunday, to finish the funeral rituals.
Most Christian churches of today remember the happenings of the Passover in a ceremony or sacrament known as the Lord’s Supper. Jesus is regarded as the sacrificial lamb whose blood was shed for our sins. In first Corinthians 5: 7 we find these words, “For Christ, our paschal lamb, has been sacrificed.” RSV
Now you know the rest of the story which tells us when it happened and why many Christians will celebrate Easter this coming weekend.