Remember the former things of old, For I am God, and there is no other; I am God, and there is none like Me, Declaring the end from the beginning, And from ancient times things that are not yet done, Saying, 'My counsel shall stand, And I will do all My pleasure,'
Jesus' sacrifice for man's sins on the cross fulfilled prophecies made hundreds of years in advance by prophets speaking the Word of God. They were able to make the predictions because God's Spirit told them what to say. After all, God knows the end from the beginning and had a plan for man's redemption from sin from the beginning of the world. But the Lord's timing of His Atonement for sins also fulfilled the purpose of the Hebrew Feasts that Israelites had observed for hundreds of years, too.
When Jesus rode into Jerusalem on Palm Sunday in 32 A.D., He was fulfilling the prophecy of Zechariah 9:9 made some 500 years before:
Rejoice greatly, O daughter of Zion! Shout, O daughter of Jerusalem! Behold, your King is coming to you; He is just and having salvation, Lowly and riding on a donkey, A colt, the foal of a donkey.

Daniel 9:25 predicted this amazing event as well:
Know therefore and understand, That from the going forth of the command To restore and build Jerusalem Until Messiah the Prince, There shall be seven weeks and sixty-two weeks; The street shall be built again, and the wall, Even in troublesome times.
Seven weeks and sixty-two weeks translate to 483 Hebrew years (composed of 360 days each). 483 years after King Artaxerxes gave the decree to rebuild the city in Nehemiah 2:-1-9, Messiah, the Prince, presented Himself as King when He rode into the city of Jerusalem on a donkey and colt. [1] He was greeted as King with shouts of Hosanna: (Save Us!)
But what is amazing is that this day that Jesus rode into Jerusalem was also the day traditionally known as Lamb selection day for the Passover feast. On that day, an unblemished male lamb was to be selected for the traditional Passover sacrifice for sin. Jesus, being the perfect unblemished, sinless man, was in effect the ultimate Passover Lamb who would take away all the sins ever committed past and future. So, God, in His perfect timing, planned Jesus' triumphant entry into Jerusalem to coincide with Lamb selection day.
Of course, on the first day of Passover, Friday, Jesus died on the cross at approximately 3PM, which was the time that the Passover lamb was traditionally slain for sins every year! Thus God's perfect plan of Jesus being the true Passover Lamb slain for sins was fulfilled.
Now from the sixth hour until the ninth hour there was darkness over all the land. And about the ninth hour Jesus cried out with a loud voice, saying, "Eli, Eli, lama sabachthani?" that is, "My God, My God, why have You forsaken Me?" Some of those who stood there, when they heard that, said, "This Man is calling for Elijah!" Immediately one of them ran and took a sponge, filled it with sour wine and put it on a reed, and offered it to Him to drink. The rest said, "Let Him alone; let us see if Elijah will come to save Him." And Jesus cried out again with a loud voice, and yielded up His spirit. Then, behold, the veil of the temple was torn in two from top to bottom; and the earth quaked, and the rocks were split,
That Jesus' payment for sins was favorably received by God the Father was shown when the veil of the temple was torn in two, allowing God's Spirit to come out from the area of the Most Holy Place. Now, God's Spirit dwells in the heart of those Believers who have repented from sin and placed their faith in Jesus for their salvation. If Jesus had never paid the penalty for our sins, then the indwelling of the Holy Spirit would not be possible.
In the Hebrew calendar, after the Passover festival is completed, the Festival of Unleavened Bread begins.
And Moses said to the people: "Remember this day in which you went out of Egypt, out of the house of bondage; for by strength of hand the Lord brought you out of this place. No leavened bread shall be eaten. On this day you are going out, in the month Abib. And it shall be, when the Lord brings you into the land of the Canaanites and the Hittites and the Amorites and the Hivites and the Jebusites, which He swore to your fathers to give you, a land flowing with milk and honey, that you shall keep this service in this month. Seven days you shall eat unleavened bread, and on the seventh day there shall be a feast to the Lord. Unleavened bread shall be eaten seven days. And no leavened bread shall be seen among you, nor shall leaven be seen among you in all your quarters. And you shall tell your son in that day, saying, 'This is done because of what the Lord did for me when I came up from Egypt.' It shall be as a sign to you on your hand and as a memorial between your eyes, that the Lord's law may be in your mouth; for with a strong hand the Lord has brought you out of Egypt. You shall therefore keep this ordinance in its season from year to year. Exodus 13:3-10
The 7 day festival of the Unleavened Bread entailed the Jews removing all of the yeast from their homes and cooking only bread that would not rise. They were commanded to remove the yeast from their homes and went to great lengths to ensure that they had done so. In the ultimate fulfillment of this event, Jesus died and was laid in the tomb and He rose from the dead during the time period of the Feast of Unleavened Bread. He is and was the true Bread of Life. He was even born in Bethlehem which means: "House of Bread". The point is that Jesus is the manna from Heaven that was provided for the people of Israel. He was also their sole provider during their 40 year pilgrimage in the desert. And He is the sole provider of Salvation and the restoration of an intimate relationship with the Holy God of Israel.
Therefore they said to Him, "What sign will You perform then, that we may see it and believe You? What work will You do? Our fathers ate the manna in the desert; as it is written, 'He gave them bread from heaven to eat.' "Then Jesus said to them, "Most assuredly, I say to you, Moses did not give you the bread from heaven, but My Father gives you the true bread from heaven. For the bread of God is He who comes down from heaven and gives life to the world." Then they said to Him, "Lord, give us this bread always." And Jesus said to them, "I am the bread of life. He who comes to Me shall never hunger, and he who believes in Me shall never thirst. - John 6:30-35
The correlation of all of the Easter week events with Jewish Feasts is too eerie to be a random coincidence. The timing is according to God's perfect plan made from the beginning of Creation.
The climatic Easter event of Jesus' resurrection from the dead took place on the day of the beginning of the Feast of the Harvest. It was another of the festivals that the Israelites were commanded to observe each year.
"Also {you shall observe} the Feast of the Harvest {of} the first fruits of your labors {from} what you sow in the field; also the Feast of the Ingathering at the end of the year when you gather in {the fruit of} your labors from the field. - Exodus 23:19

Jesus is the firstfruits of Harvest of the Resurrection. The rest of the Harvest will take place when all who have put their faith in Him are resurrected in the Age to come.
Your dead shall live; Together with my dead body they shall arise. Awake and sing, you who dwell in dust; For your dew is like the dew of herbs, And the earth shall cast out the dead. - Isaiah 26:19
But now Christ is risen from the dead, and has become the firstfruits of those who have fallen asleep. For since by man came death, by Man also came the resurrection of the dead. For as in Adam all die, even so in Christ all shall be made alive. But each one in his own order: Christ the firstfruits, afterward those who are Christ's at His coming. - 1st Corinthians 15:20-23
[1]
Please see Sir Robert Anderson's book:The Coming Prince for explanation on how this prophecy was fulfilled exactly by this event.