In Alma 57:5 it says, “thus ended the twenty and eighth year,” but contrary to usual practice, nothing had been said of the end of the 27th year or the beginning of the 28th year. Why? Is this an error in dating? Perhaps a plausible explanation is in order.
The reason Helaman uses dating in the first place is to report the action taking place on the western front, while assuming that the background he has explained remains understood.
Consider the phrases Helaman uses to describe the time sequence of events:
26th year: The year “ended” (Alma 56:20) but there is no mention of a “commencement.”
27th year: The “commencement” is mentioned (Alma 56:20), the “second month” (Alma 56:27), the “seventh month,” but not an “end.”
28th year: Only an “end” is mentioned (Alma 57:5).
29th year: A “commencement” is mentioned (Alma 57:6) and a “latter end” (Alma 58:38), but not true “end” is referred to.
This means that we fail to have both a specific “commencement” and a true “end” in every year mentioned; we only have a stated “commencement” in two out of four years; and we only have a designated final “end” in two out of four years. Thus, while the omission of the end of the 27th year and the commencement of the 28th year is significant, it is not overwhelming evidence in and of itself of a mistake. By comparison, while Mormon seems to mention the years in sequence during this time period in his abridgment (21st year ---> 31st year), he seems to have no problem in skipping over almost four years without a mention to the death of Helaman in the 35th year (Alma 62:52).
In summary, what I have found consistent in the writings of both Helaman and Mormon, is that the sequence of their chronology has been not only plausible, but probable.
My analysis of the second major point of Helaman’s epistle might give some understanding for the reason that Helaman would not mention either the ending of the 27th year or the beginning of the 28th year. I believe it has to do with his description of action versus the background setting. There are some key background scriptures just before and after the action at Antiparah which demonstrate the reason why Helaman skipped some references in his dating. The first concerns the attitude of the Nephites and Lamanites:
And now they (Antipus and his men) were determined to conquer in this place (Judea) or die; therefore you may well suppose that this little force which I brought with me, yea, those sons of mine, gave them great hopes and much joy.
And now it came to pass that when the Lamanites saw that Antipus had received a greater strength to his army they were compelled by the orders of Ammoron to not come against the city of Judea, or against us, to battle
And thus were we favored of the Lord; for had they come upon us in this our weakness they might have perhaps destroyed our little army; but thus were we preserved. Alma 56:17-19)
Thus it was the intention of the Nephites to maintain what they had. Likewise, after the arrival of Helaman and his 2000 warriors, apparently Ammoron and the Lamanites also thought it was better not to attempt a direct attack against a fortified Nephite city. The stratagem of Antipus and Helaman which eventually led to the fall of Antiparah was not a direct attack on a fortified city, because the cost of victory would have been too great. What they did was to ambush Lamanite forces attacking their supply lines. Furthermore, despite the preparations for an attack on Antiparah by Helaman and his men, we are not told whether or not he would have actually attacked. But whether the Nephite preparations were a bluff or not, Antiparah did not represent the strong fortification that it once was.
Now, let us get down to the apparent crucial omission of the end of the 27th year and the commencement of the 28th year. Concerning the background attitude of maintenance and defense by both the Lamanites and the Nephites, we see that during the time period omitted this attitude apparently did not change! Coincidentally, Moroni on the east coast also used part of the 28th year for maintenance. Mormon’s description of this process adds some insight:
And it came to pass that [Moroni] did no more attempt a battle with the Lamanites in that year, but he did employ his men in preparing for war, yea, and in making fortifications to guard against the Lamanites, yea, and also delivering their women and their children from famine and affliction, and providing food for their armies. (Alma 53:7)
Thus, the background setting of maintenance and defense did not change on the west coast until the commencement of the 29th year. Helaman explains why the 29th year (and not the 28th year) suddenly became important:
And it came to pass that in the commencement of the twenty and ninth year, we received a supply of provisions, and also an addition to our army, from the land of Zarahemla, and from the land round about, to the number of six thousand men, besides sixty of the sons of the Ammonites who had come to join their brethren, my little band of two thousand. And now behold, we were strong, yea, and we had also a plenty of provisions brought unto us. (Alma 57:6)
According to Helaman’s reasoning, the whole situation had changed! The Nephites were now in a military position to attack! Helaman writes:
And it came to pass that it was our desire to wage a battle with the army which was placed to protect the city Cumeni.
And now behold, I will show unto you that we soon accomplished our desire (Alma 57:7-8)
In summary, although Helaman definitely makes an omission in specific dates of his epistle, the omission of the 28th year was not the only omission of phrases which Helaman used in dating, and as such does not constitute a mistake. Helaman’s writings are definitely in sequence. The reason for the omission has to do with the non-changing background setting of the Nephite & Lamanite defensive military posture. In essence, there was nothing significant for Helaman to report that happened in the 28th year. The circumstances that led to the Nephite policy change of attacking rather than defending took place in the 29th year and were duly noted by Helaman. [Alan C. Miner, Personal Notes]