

Pentecost, therefore, always fall on the 6th of Sivan which does not always occur on a Sunday. To draw this conclusion, we must follow the directions of the Holy Scripture in numbering the days from Passover to Pentecost.
Pentecost begins seven (7) weeks from the 15th of Abib (Nisan) Any seven calendar days constitute a week However, any seven days does not determine the week, which begins on the 1st day and ends on the seventh day. Therefore, to better understand the Bible's directions of numbering seven sabbaths, we must understand that any period of sevens are considered a sabbath when the Word of God states it. An example is found in Leviticus 25:1-7, where God directs Israel to keep a sabbath for the land. And continuing in verses 8-17, an extended sabbath of years is commanded. Therefore, according to scripture, there is a sabbath of days, weeks, months and years. All of these periods can be called sabbath periods because they constitute seven time sevens. A sabbath of weeks occurs from the 15th of Abib to the 6th of Sivan, which 5 the day of firstfruits.
Upon their arrival in the new land, Israel was ordered by God to wave a sheaf of the firstfruits of their harvest on the morrow after the sabbath (Leviticus 23:9-11). Which sabbath? The sabbath of Abib the 14th. Therefore, Israel waved the sheaf of firstfruit on the 15th of Abib. They were ordered to began counting the days from the date of the 15th and number seven sabbaths, not seven 7th day sabbaths, but seven weeks of sabbath. Conclusive proof of this can be found in Joshua 5:10-12.
The children of Israel kept the Passover on the fourteenth day of the month at even in the plains of Jericho. They ate of the old corn of the land on the morrow after the Passover (they ate the old corn on the 15th of Abib, which is the morrow after the Passover Joshua 5:11). God had commanded them not to eat bread, nor parched corn, nor green ears, until the selfsame day they offered the sheaf of wave offering (Leviticus 23:14). To begin numbering the days for Pentecost, they were commanded to begin the count from the morrow after the sabbath, from the day (not several days later, and start counting from the seventh day sabbath) they brought the sheaf of wave offering (Leviticus 23:15). Therefore, the sabbaths in question were not the seven day sabbath but the feast sabbaths as seen in Joshua 5:10-12. The manna ceased on the 16th of Abib, the morrow after they had eaten of the old corn of the land (Joshua 5:12).
We can clearly see that the count for Pentecost begins from the 15th of Abib. Seven weeks must be complete: "begin to number the seven weeks from such time as thou begin nest to put the sickle to the corn." (Deuteronomy 16:9). Israel did not harvest the corn of the new land until the manna ceased, and the manna ceased on Abib the 16th (Joshua 5:12). If we began counting from the 15th of Abib until the 6th of Sivan, we will always complete 50 days (seven weeks plus one day). Each year the feast falls on a fixed date, Sivan 6th.
We are commanded to observe this feast of firstfruits (Leviticus 23:9-11). For God has ordained his feasts as statutes forever (Leviticus 23:1-3). God fulfilled his word to Abraham and his seed by given them the land of promise. The memorial of entering the land of Canaan, is celebrated in the feast of firstfruits in the offering of the firstfruit of the land to God. The Holy Ghost, which was the firstfruit of the Spirit, was given on the day of this great Feast. The Holy Ghost fell on the 120 in the upper room, on the 6th Of Sivan, the Day of Pentecost (Acts 2:1-4).