Geographic: Of course we have seen a Lamanite attack on Ammonihah before. In the lightning raid carried out after the expulsion of the Anti-Nephi-Lehies from the land of Nephi, the target was Ammonihah. The hypothesis presented at that time was that this was a relatively quick target, even though in the more northern parts of Nephite territory because it was approachable from a shore march that kept away from the rest of the Nephite cities. It would appear that this approach did not change in the few years between these two incidents. It is also quite probable that with the success of the first raid on Ammonihah, it would have been presumed that this second approach at that same location might have been equally successful.
Of the general layout of this approach to Nephite territory, Sorenson suggests:
“Around 80 B.C. just after Alma’s experience there, “the Lamanites had come in upon the wilderness side, into the borders of the land, even into the city of Ammonihah” (Alma 16:2) and destroyed it. Nine years later they came in by the same route, expecting easy pickings against the partially rebuilt city (Alma 49:1-3). In both cases, it is clear, the Lamanite force had journeyed from the land of Nephi northward along the coastal wilderness strip “on the west of Zarahemla” (Alma 22:28); the Nephites never defended that zone, it seems. (They probably never even occupied it seriously, for their record mentions no settlement, no event there.) When the attackers got far enough northward, they “went over into the borders of the land of Zarahemla, and fell upon the people who were in the land of Ammonihah” (Alma 25:2). The “over” is precisely correct, for they would have had to cross the western wilderness chain of mountains from the coast to get to Ammonihah, the first major city they came to on the main route… The fit of text to terrain would be difficult to improve.” (John L. Sorenson. An Ancient American Setting for the Book of Mormon. FARMS 1985, p. 203).
Social: It may seem too simplistic to note, but it is still important to note that they Nephites calculated time on the basis of at least three divisions of time, the year, month, and day. We have numbered months and numbered day. The Nephites may or may not have had month names as we do, but there is never any indication of them if they did. Similarly, they may or may not have had day names.
It is also possible that the Nephites used a seven day week as a unit of time measurement, though the evidence for this is limited, and there is the possibility that the evidence is misleading.
The brass plates certainly had the record of the seven days of creation that formed the basis of the Israelite conception of the seven day week. We know that Mosiah knew of the seven day week from that source (if no where else) because he references it in his reprise of the ten commandments:
Mosiah 13:17-20
17 Six days shalt thou labor, and do all thy work;
18 But the seventh day, the sabbath of the Lord thy God, thou shalt not do any work, thou, nor thy son, nor thy daughter, thy man-servant, nor thy maid-servant, nor thy cattle, nor thy stranger that is within thy gates;
We have three more uses of the term “week” in the Book of Mormon:
Mosiah 18:25
25 And there was one day in every week that was set apart that they should gather themselves together to teach the people, and to worship the Lord their God, and also, as often as it was in their power, to assemble themselves together.
Alma 31:12
12 Now, when they had come into the land, behold, to their astonishment they found that the Zoramites had built synagogues, and that they did gather themselves together on one day of the week, which day they did call the day of the Lord; and they did worship after a manner which Alma and his brethren had never beheld;
Alma 32:11
11 And moreover, I would ask, do ye suppose that ye must not worship God only once in a week?
Of these three, the two from Alma 31 refer to the same situation, and an intriguing one because it comes from the Apostate Zoramites. It would appear, however, that rather than a completely apostate idea, the concept of meeting once a “week” to worship God is really a Nephite tradition, since we see it in Mosiah as well.
What is difficult to tell is whether or not what we see as “week” in the Book of Mormon meant the same thing to the Nephites as it does to us. It certainly could, since the Nephites had both a tradition from the Old World and the brass plates to suggest a seven-day week. The only thing that might counter the probability of the continuation of this pattern would be the competing calendars of the non-Nephite world. The only evidence that might suggest that the seven day week did not hold the same meaning for the Nephites as it did in the Old World (or the modern world) is that the number seven does not appear to be significant in the Book of Mormon. In Israelite symbology, the seven creative periods fostered a large number of symbolic number references based on the number seven. Any computer search of the Old or New Testaments for “seven” or “seventh” will indicate a large number of times when that number appears, and typically in situations where it is symbolic rather than a count. On the other hand, seven only appears in the Book of Mormon in counts. The lack of symbolic use of the number seven suggests that there was a conceptual break with the Old World symbol system, and this was one of the casualties. The other explanation for the lack of sevens in the Book of Mormon is that the entire text appears to be relatively devoid of symbol numbers. Most numbers in the Book of Mormon appear as some form of count.
It is just possible that the “week” shows up in the text because it was one of Joseph Smith’s assumptions in translation, a process that we have seen before. However, since there is clear indication that they knew of, and endorsed, the brass plates that did clearly indicate the seven-day week, the safest assumption is that it was continued in Nephite society, even though it was absent from the surrounding cultures.