The word Pentecost means fiftieth in Greek, indicating the process of counting fifty days. This counting is a vital part of the day of Pentecost, as God instructs us to count either seven weeks or fifty days, both methods leading to the same day. The significance of counting fifty days is tied to the idea of measuring time, which symbolizes evaluation and judgment. The fifty days from the Wavesheaf day to Pentecost represent the time of our conversion, from coming out of the world until the time of harvest, symbolizing our spiritual growth and preparation for salvation. This period of fifty days underscores the finite nature of our time for conversion, reminding us that our day of salvation is limited.

The period from the wavesheaf to Pentecost lasts fifty days. This time is dedicated to the theme of the harvest of the firstfruits and God's role in it. It begins with the waving of the sheaf of firstfruit barley, representing Christ, and concludes with the waving of two loaves of leavened bread, symbolizing God's acceptance of His people into His Kingdom. During these fifty days, the emphasis is on the work that God's people must do, both externally in their fields and internally in their dwellings, to produce godly character and growth. This period pictures intense labor of sowing and reaping, with the goal of being offered before God as an acceptable offering.

The Feast of Pentecost is unique among the holy days because it requires counting either seven weeks or fifty days from a particular day, a weekly Sabbath, rather than being assigned a fixed date like the other holy days. This count always concludes on a Sunday, the day after the seventh Sabbath. The term Pentecost, meaning "fiftieth" in Greek, directly relates to this count of fifty days as instructed in Leviticus 23:15 and 16. This period of fifty days begins around the time of Passover and the Days of Unleavened Bread, symbolizing a time of redemption and the process of putting away sin and putting on righteousness, culminating in Pentecost, which represents the harvest of the firstfruits. This fifty-day period is analogous to the time of conversion, likened to the approximate fifty years of adult life from age twenty to seventy, as discussed in the context of Numbers 1:1-3 and Psalm 90:10.

The change from observing Pentecost on Monday to Sunday resulted from correcting an error in counting fifty days. Herbert Armstrong counted exclusively in the manner of an English-speaking person, but the Bible was written in Hebrew, and Hebrew-speaking people count inclusively. Leviticus 23:15 and 16 direct a count from the day after the Sabbath in a manner that places the fiftieth day on Sunday when the inclusive method is applied. All other holy days fall on fixed dates each year, but Pentecost requires this count, and the correct method produces a Sunday observance on the fiftieth day. The word from in the instruction must be understood from a Hebrew point of view, which begins the count on the day in question rather than the day after. Acts 2:1 states that the day of Pentecost was fully come, and the Greek phrase indicates the action of fulfilling the fiftieth day was taking place. The word Pentecost itself means fiftieth, not fifty-first, and the verse provides no authority for extending the observance to a Monday. Translations such as the New English Bible render the phrase as the day of Pentecost running its course, confirming that the events occurred during the fiftieth day of the count.