The Spring Feasts, as the name implies all occur in the spring and early summer time, and their timing is based on the Jewish Lunar calendar. These are the Lord's Feasts, not the Feasts of the Jews, they are God's and He has a purpose for each of them. They each have a different scriptural meaning, the Spring Feasts show the Messiah and bring the gift of salvation to all Jew and Gentile. The Fall feast will be fulfilled at a date and time yet to be made known.

Each of the Spring Feasts has been fulfilled and on the exact date in the Hebrew calendar that God appointed them, even down to the exact times certain events happened in the Temple, I will explain more on this in the articles for each feast a brief resume is given below. But you must remember that just because the spring feasts have been fulfilled that does not mean we can stop celebrating them, there is a reason God said that these feasts are His feasts and that they are to be kept every year for evermore and they are Holy days, we are to proclaim them or in other words teach them at the correct time that has been chosen by God. So why does this not happen in most gentile churches today? I would guess most of them do not believe that the Old Testament is relevant anymore and they also believe that these are the Jewish Feasts not Gods Feasts and so not for the gentiles. Another way to see this is that these feast have been hidden from many and the revelation of their meaning is not revealed until you beg God to see the truth and this is the same for both Jew and Gentile alike. In not seeing the meanings of these feasts, the Church has been robbed of parts of God's plan, but in time the eyes that have been blinded will be opened.

Passover - (Pesach) on Nissan 14 was fulfilled with Jesus entry into Jerusalem 2000 years ago as the sacrificial Lamb, He came into Jerusalem riding on a donkey, the symbol of coming in peace not war. He was inspected and questioned in the Temple for the next 4 days and then crucified on the cross He died at the same time as the Passover Lambs were sacrificed in the Temple, His life blood poured out and anointed the mercy seat, paying the price for us all for failing to keep the first covenant.

Unleavened Bread - (Hag HaMatzot) on Nissan 15 fulfilled with Jesus burial in the tomb. Leaven or yeast in the Bible symbolises sin and evil. Unleaven bread, eaten over a period of time, days, symbolises a Holy walk. Jesus was described as "the bread of life" and He was born in Bethlehem, which, in Hebrew means "House of Bread".

First Fruits - (Yom HaBikkurim) on Nissan 17 fulfilled with His resurrection. Remember the verses in Matthew 27: 51 - 53, when Jesus died on the cross an earthquake happened and the graves on the Mount of Olives were opened. It goes on to say when Jesus arose a number of the saints buried in those graves arose and went into Jerusalem and were seen by many. Why do you think Jesus said to Mary in the Garden dont touch me? What happened to those other saints who arose as well? My guess is that they ascended along with Jesus who in the capacity of the High Priest presented them to the Father as the First Fruit offering. If Mary had touched him at that time he would have been defiled and so He could not have fulfilled the office of the High Priest and presented the First Fruits Offering to His Father.

The Feast of Weeks (Pentecost) - (Shavu'ot) on Sivan 7 with the giving of the Holy Spirit. Do you realise that the nation of Israel were celebrating Pentecost 2000 years before the Holy Spirit fell in Jerusalem after the Ascension of Jesus, the giving of the Holy Spirit is just the fulfillment of the feast. The feast marks the giving of the Torah at Mount Sinai, 7 weeks after the Exodus and the crossing of the Red Sea the people are gathered at the foot of Mount Sinai as God descended onto the mount amidst thunder, lightening, billowing smoke and fire, along with some very loud blasts on a shofar(trumpet made of a rams horn). God shouted down the Ten commandments this was the baptism with the Holy Spirit Exodus style, trumpets and shouting so loud that the people thought they were going to die.

All four of these feasts have been fulfilled but that does not mean that they are no longer relevant, Jesus showed the full meaning of the Feasts. They started when God gave the instructions to Moses on Mount Sinai during the Exodus out of Egypt and they are relevant all the way through to the end of the Book of The Revelation. They are and will be celebrated on the same date every year as they have always been.

I like the King James version for this type of study, one tip you can see here is everywhere you see "LORD" in the King James you can translate this as the Name of God "YHVH", Yehovah and certainly not Yahweh (that will be for another article later). The entire plan of God for our salvation is seen in this one chapter, each feast represents a step on our path from here to the New Jerusalem, we are waiting for the fall feasts to be fulfilled.

King James Bible : Leviticus 23:1-22
1: And the LORD spake unto Moses, saying,
3: Six days shall work be done: but the seventh day is the sabbath of rest, an holy convocation; ye shall do no work therein: it is the sabbath of the LORD in all your dwellings.
4: These are the feasts of the LORD, even holy convocations, which ye shall proclaim in their seasons.

Passover:

5: In the fourteenth day of the first month at even is the LORD'S passover.

Unleavened Bread

6: And on the fifteenth day of the same month is the feast of unleavened bread unto the LORD: seven days ye must eat unleavened bread.
7: In the first day ye shall have an holy convocation: ye shall do no servile work therein.
8: But ye shall offer an offering made by fire unto the LORD seven days: in the seventh day is an holy convocation: ye shall do no servile work therein.

First Fruits

9: And the LORD spake unto Moses, saying,
10: Speak unto the children of Israel, and say unto them, When ye be come into the land which I give unto you, and shall reap the harvest thereof, then ye shall bring a sheaf of the firstfruits of your harvest unto the priest:
11: And he shall wave the sheaf before the LORD, to be accepted for you: on the morrow after the sabbath the priest shall wave it.
12: And ye shall offer that day when ye wave the sheaf an he lamb without blemish of the first year for a burnt offering unto the LORD.
13: And the meat offering thereof shall be two tenth deals of fine flour mingled with oil, an offering made by fire unto the LORD for a sweet savour: and the drink offering thereof shall be of wine, the fourth part of an hin.
14: And ye shall eat neither bread, nor parched corn, nor green ears, until the selfsame day that ye have brought an offering unto your God: it shall be a statute for ever throughout your generations in all your dwellings.

Pentecost

15: And ye shall count unto you from the morrow after the sabbath, from the day that ye brought the sheaf of the wave offering; seven sabbaths shall be complete:
16: Even unto the morrow after the seventh sabbath shall ye number fifty days; and ye shall offer a new meat offering unto the LORD.
17: Ye shall bring out of your habitations two wave loaves of two tenth deals: they shall be of fine flour; they shall be baken with leaven; they are the firstfruits unto the LORD.
18: And ye shall offer with the bread seven lambs without blemish of the first year, and one young bullock, and two rams: they shall be for a burnt offering unto the LORD, with their meat offering, and their drink offerings, even an offering made by fire, of sweet savour unto the LORD.
19: Then ye shall sacrifice one kid of the goats for a sin offering, and two lambs of the first year for a sacrifice of peace offerings.
20: And the priest shall wave them with the bread of the firstfruits for a wave offering before the LORD, with the two lambs: they shall be holy to the LORD for the priest.
21: And ye shall proclaim on the selfsame day, that it may be an holy convocation unto you: ye shall do no servile work therein: it shall be a statute for ever in all your dwellings throughout your generations.
22: And when ye reap the harvest of your land, thou shalt not make clean riddance of the corners of thy field when thou reapest, neither shalt thou gather any gleaning of thy harvest: thou shalt leave them unto the poor, and to the stranger: I am the LORD your God.

I feel I have to give a warning here about those who say that we must obey and celebrate these feasts.
King James Bible : Romans 14:
5: One man esteemeth one day above another: another esteemeth every day alike. Let every man be fully persuaded in his own mind.
6: He that regardeth the day, regardeth it unto the Lord; and he that regardeth not the day, to the Lord he doth not regard it. He that eateth, eateth to the Lord, for he giveth God thanks; and he that eateth not, to the Lord he eateth not, and giveth God thanks.
We are clearly told here by the Apostle Paul that if you want to remember and celebrate a day unto the Lord, then do it, but if you do not wish to keep the celebration then dont. We are not allowed to judge anyone for doing it one way or the other. My thoughts here are why do you wish to hold onto the shadow picture of Jesus when you have the real Jesus living with you and in you.