Nephi did not slay Laban in vain in obtaining the books of Moses engraved upon the “plates of brass”. Truly the LORD guided Lehi’s company to a land where they could keep the Law of Moses “in all things”. This must have included seasonal ordinances based in the temperate Northern Hemisphere. Given the calendar constraints of the Law of Moses, how is the Book of Mormon’s prophetic 600 year chronology reconciled with current biblical history?

The Book of Mormon records that “a Messiah” would come “six hundred years” from the time that the prophet Lehi departed Jerusalem. (1 Nephi 10:4; 19:8; 2 Nephi 25:19) The ancient American historian, Mormon further records that Lehi and his family “came out of Jerusalem in the first year of the reign of Zedekiah, the king of Judah.”   (Genealogical preface to 3 Nephi)

Some early historical works list Zedekiah’s reign as commencing 599 years before the “Christian era”. (Appendix Dissertation V to The Complete Works of Josephus; translated by William Whiston, 1867 – 1752) Assuming that the Lord was actually born near “Anno Domini” in 1 or 2 CE, this appears to support the “six hundred years” mentioned in the Book of Mormon. No problem - right? Well, not exactly. More recent estimates of Zedekiah’s first regnal year mark 597 BCE (Before the Common Era), and many scholars now see the birth of Yeshua fitting closer to 5 BCE. (Jack Finegan, Handbook of Biblical Chronology, Princeton University Press, 1964, pp. 320-323, 325) In that case, the Book of Mormon prophecy appears to be off by several years!  

In reading the Book of Mormon, have you noticed that while Lehi’s company were journeying to the Promised Land, they didn’t describe the passage of time in terms of months, but in terms of “days” and “years”? (1 Nephi 16:15, 17, 33; 17:4, 7, 20-21, 52; 18:9, 23)

At times in their journey, the seasons and phases of the moon stopped making sense to them - until they arrived in the Promised Land!

“Shanah” comes from the Hebrew word for “change” (שנה). The Hebrew word “shanah” is translated “year”, but “shanah” is not quite the same as a year in the modern sense defined by the Gregorian calendar.

The Promised Land “shanah” or Israelite year is variable; either 12 or 13 lunar months (true “moonths”). How long the Promised Land “shanah” is depends on agriculture – in particular the ripening of barley in the fields. Karaite Jews, relying almost exclusively on Torah (Law of Moses), understand this. They understand that before the Babylonian captivity, the designation of the first month, year to year, depended on a particular crop. (Click here for more on the meaning of "aviv" and the importance of barley in ancient Israelite culture)

The simplicity and genius of the LORD’s Promised Land calendar is its ability to designate months by the moon, yet track the seasons by adding a leap month as needed.

The divinely appointed first month in the Promised Land always occurrs in the spring of the Northern Hemisphere following the “aviv” of barley. “Aviv” or “Abib” (KJV) is a key stage of barley ripening. Ripened barley was essential for the springtime grain offering performed yearly by the priests in the Temple during the month of the “aviv”. (Exodus 12:1-2; 13:4, 10; 23:15; 34:18, Leviticus 23:10-12, Deuteronomy 16:1) This was a requirement of the Law of Moses that must also have been satisfied in the American land of Israel – “choice above all other lands”. (2 Nephi 10:19) Certain Priesthood ordinances could only be performed at “the place which the LORD thy God shall choose to place his name”. (Deuteronomy 16:5) The Book of Mormon indicates that the LORD had chosen to place his name in more than one land.

The Book of Mormon symbolically relates the springtime “first-fruits” barley offering to resurrection. (2 Nephi 2:8-9, Jacob 4:11) The wave offering of barley occurred prophetically on the first day of the week (the day following Shabbat) during the week of Passover. (Leviticus 23:10-11)

If the barley in the fields (Mosiah 9:9) was not mature enough at the end of the twelfth month, then the designation of the first month of the year had to be postponed an extra month. (Alfred Edersheim, The Temple – Its Ministry and Services As They Were at the Time of Jesus Christ, Ch. 10, pg. 136, 64/131)

When Lehi left Jerusalem in the first year of the reign of Zedekiah ^[1], being on a journey, Lehi and his company were excused from observing certain seasonal ordinances on time. (Numbers 9:9-13) There was even a reasonable provision in the Law allowing them to eat forbidden things (including blood) in order to save their lives. For a man is to “live in” the statutes of the LORD - not die because of them. (Leviticus 18:5, 1 Nephi 17:2)

Nephi had killed a man (Laban) so that future generations in the Promised Land would have the Law of Moses in detail to obey. (1 Nephi 4:14-16) Nephi would later attest that the LORD had in fact led his people to a land where they could keep the Law of Moses “in all things”. (2 Nephi 5:10)

Until they and their seed from Jerusalem could be established in the Promised Land, they were excused from observing some of the ordinances of the Law. Much of the Law is Promised Land based. (E.g. Leviticus 19:23; 23:10; 25:2) While journeying, Lehi was not always required to keep track of seasons and months – nor indeed could he! The strange and varying seasons encountered during their travels could not be counted on for ordering the year.

During their voyage, the progress of the lunar phases appeared to change from right to left (seen from the Northern Hemisphere; same as the direction of Hebrew writing, and the writing on the Book of Mormon plates; History of the Church, Vol. 1, pg. 71) to left to right (seen from the Southern Hemisphere), back to the familiar right to left again, as they arrived in the American Promised Land in temperate North America. In the American Promised Land, the constellations and lunar phases were again familiar, but during their voyage, The cycles of the moon (about 29.5 days per cycle) would not always coordinate with the seasons – so the pilgrim Lehi could not rely on cycles of the moon and seasons to accurately tell the “year”.

Months are never mentioned in the account of Lehi’s journey. The units of time that were kept track of were “days” and “years”. If agricultural seasons could not be relied on to determine the length of a “shanah” (“year”), how did Lehi measure “shanim” (“years”) during his travels to the Promised Land?

Lehi’s company could always discern the passing of days. The journey “shanah” must therefore have been based on a set number of days. Lehi could have relied on a fixed number of days to define a “shanah”, independent of the cycles of the moon and the seasons.

The journey “shanah” may have been divinely appointed. (1 Nephi 19:8)

When did Lehi start counting “years” to Messiah’s coming? From his Jerusalem departure we are told! (1 Nephi 10:4; 19:8, 2 Nephi 25:19) It must therefore have been the fixed journey “shanah” and not the adjustable Promised Land “shanah” that was the prophetic unit of time marking the Messiah’s coming in “six hundred years”.

The Nephites could have easily distinguished these two units by masculine and feminine plural endings. Prophetic journey “years” would be “shanim”, and Promised Land years would be “sh’not”. Both of these plural forms are found in Hebrew scripture, and both are translated “years”. The distinction is lost in translation; but it is possible to discern between the two measures of time in Nephite scripture. Lehi’s prophetic shanim are always measured from the time he left Jerusalem.

Remember, “shanim” (pronounced “shah-neem”) is Hebrew for “years”. The masculine plural ending (-im) is appropriate in light of the count to his (Messiah’s) coming. Examples of “years” spelled “shanim” in Hebrew scripture are: Exodus 21:2, Leviticus 25:21.  

“Sh’not” (pronounced “shehn-oat”) is also Hebrew for “years”. The feminine plural ending (-ot) is appropriate for designating years in the American Promised Land following the divine Israelite calendar. (Psalm 104:19) The covenant land (ha-aretz) is spoken of in Hebrew scripture as feminine. (E.g. Leviticus 25:22-23; 26:34, Helaman 11:17) Examples of “years” spelled “sh’not” in Hebrew scripture are: Deuteronomy 32:7, Isaiah 38:15.

Faithful Nephites in America continued to tally Lehi’s journey “shanim” long after settling in the Promised Land. They did this not as a requisite calendar, but for the sole purpose of counting “years” to Messiah’s coming. Lehi’s journey “shanah” could not be used to establish months of the festival calendar, so the count of “years” from Lehi’s departure wasn’t so much a calendar as it was a tally.

Once the Nephites were established in the Promised Land, the Law of Moses set the practical calendar which became Nephite custom. The calendar became convention whether or not the people were righteous, as in the Biblical Promised Land. (Isaiah 1:11-17) The passage of time measured in Lehi’s journey “years”, on the other hand, became a purely religious exercise with an eye single to Messiah’s coming.

Nephite months in the American Promised Land were essentially the same numerated Promised Land months or Israelite months that we find mentioned in the Bible. The very same calendar was used by the Nephites that is so integral to the Law of Moses – for they and converted Lamanites “strictly” kept the Law “in all things”. (2 Nephi 5:10; 11:4; 18:10, 19-20; 25:24-30, Jacob 4:5, Enos 1:20-21, Jarom 1:5, 11, Mosiah 2:3; 3:14-15; 24:5, Alma 25:15-16; 30:3; 31:9, 34:14, Helaman 13:1; 15:15, 3 Nephi 25:4, Ether 12:11)

The estimated birth of Messiah near 5 or 6 BCE (having an uncertainty on the order of about a year; Matthew 2:16) is based on the lunar eclipse of 4 BCE, observed in Palestine near the time of the death of Herod “the Great”. (Josephus, Antiquities of the Jews, Chapter V.)

Nebuchadnezzar (“Nebuchadrezzar”) is believed to have ascended the Babylonian throne in 605 BCE. (Richard A. Parker and Waldo H. Dubberstein, Babylonian Chronology 626 B.C. - A.D. 75, Brown University Press, 1956, pg. 12) Subtract 19 years from 605 BCE to estimate the time of the fall of Jerusalem and the end of Zedekiah's reign. (Jeremiah 52:8-13) Add 11 to this results for the years of Zedekiah's reign (Jeremiah 52:5), and we arrive at the first regnal year of Zedekiah commencing in  597 BCE. (Jack Finegan, Handbook of Biblical Chronology, Princeton University Press, 1964, pp. 320-323, 325)

In order to determine the possible number of years between the first year of Zedekiah's reign 597 BCE (first regnal year) or 598 BCE (year of accession) and the birth of the Anointed, we should know the precision or uncertainty of the ~598, 597 BCE date.  If the precision of this date is based on astronomical observation relating to the kings of Babylon (i.e. records in the Babylonian Chronicles), this would tend to make the estimate rather precise (being based on celestial mechanics); compared to say, the radiocarbon dating of an archaeological artifact from the same time period. We need to know quantitatively how uncertain the date of Zedekiah’s first year of reign really is! Given this information, we may better propose the number of days in the journey “shanah”. Short this information we can proceed with a test based on a reasonable estimate of how many days may have composed Lehi’s journey “year”.

Let’s suppose that the journey “shanah” given to the pilgrim Lehi (his “prophet’s time”; Doctrine and Covenants 130:4) was a “perfect” period of exactly 360 days. An ideal year of 360 days is a good average between a purely lunar year (~354 days) and the solar year (~365.25 days). The number 360 is completely divisible by 12. It is the traditional number of compass degrees. By comparison the divine lunisolar Promised Land year (which tracks the seasons of the temperate Northern Hemisphere) averages in the long-term to about 365.242 days per year.

In anticipation of Messiah’s birth, all the Nephites had to do was to keep counting and recording days in groups of 360, calling them shanim “from the time Lehi left Jerusalem”, and then to keep this prophetic tally separate from the months and years (sh’not) that pertained to the Law of Moses.

In review:

·         Lehi could not have relied on the divine Israelite calendar to determine “years” while he was journeying far from both Promised Lands. He could not tell from the seasons in foreign places whether the year should be defined as 12 months or 13 months. Time from his Jerusalem departure is never given in months - this is a clue. Lehi likely relied on a revealed fixed number of days to define a year during his journey. After Lehi’s people settled in the American Promised land, they were able to keep “the commandments of the Lord, in all things according to the law of Moses.” (2 Nephi 5:10) The Nephites continued to count Lehi’s shanim separately as a prophetic count to Messiah’s coming. (1 Nephi 10:4)

·        In the American Promised Land, Nephites and converted Lamanites referenced the lunisolar Israelite calendar as they strictly kept the Law of Moses on a daily, monthly and yearly basis. (Mosiah 13:30-31) You cannot strictly keep the Law of Moses in all things and omit the divine calendar. The LORD would not have led Lehi’s people to a land where they could not have kept all the commandments. (2 Chronicles 8:12-13, 2 Nephi 5:16)

Here then are the proposed rules for Nephite scripture:

·      All “years” measured from the time Lehi left Jerusalem are 360 day shanim.

·   All other years (e.g. relating to the reign of kings or judges in the land, wars etc.) are sh’not measured according to the Israelite calendar. Nephite  sh’not therefore consist of either 12 or 13 months, tracking the seasons of the temperate Northern Hemisphere.

It’s ok for a verse to reference both measures of time. Let’s demonstrate how these different measures of time, both translated “years”, fit scripture:

We read that Mosiah son of Benjamin began to reign “in the thirtieth year of his age”, meaning that he was between his 30^th and 31^st birthdays in the land. He was 30+ Promised Land “sh’not” (Promised Land years) when he began to reign. We also read that this event corresponded to “about” 476 journey “shanim” (journey “years”) from Lehi’s departure. (Mosiah 6:4)

We read that Mosiah died in the 33^rd Promised Land year of his reign.  He was between 63 and 64 Israelite years old when he died. We are told that this event corresponded “in the whole” to 509 “years” from the Jerusalem departure. (Mosiah 29:46) We conclude that the “five hundred and nine years” is estimated in Lehi’s prophetic journey years – “shanim”.

It makes sense that in the Book of Mormon, time from Lehi’s Jerusalem departure is always measure in Lehi’s prophetic “years”; which he started counting after leaving Jerusalem; whereas months and other historical events in the land are determined according to the Israelite calendar. Again, the number of days per Israelite year, averaged over many years, is about 365.242.

The relation between king Mosiah’s age (ש₁) in Israelite Promised Land based years, and time from Lehi’s departure in journey “years” (ש₀), can be mathematically modeled as a simple linear function having slope m = 365.242/360 and intercept b₁. Like this:

(1)     ש₀  ≈  m ש₁  +  b₁

This does not mean that the Nephites had to use linear functions to keep track of time. Simple linear functions are effective for testing and for showing how scriptural dates fit.

Because b₁ is constant, an interval of time in Promised Land years (Δ ש₁) corresponds to an interval of time in journey “years” (Δ ש₀) according to the following basic formula:

(2)     Δ ש₀  ≈  m Δ ש₁

Must we deal with formulas to resolve these matters?

Well, there’s the risk of oversimplifying the problem if we don’t. Here is an example of an overly simplified argument:

·       Mosiah began his reign 476 years from Lehi’s departure. (Mosiah 6:4)

·        Mosiah died 509 years from Lehi’s departure. (Mosiah 29:46)

·        So Mosiah reigned 509 – 476 = 33 years.

Ah, but there’s a problem here: Scripture teaches that Mosiah died in the 33^rd year of his reign. (Mosiah 29:46) The 33^rd year of Mosiah’s reign started 32 years after he became king, so Mosiah actually reigned less than 33 years.

We see that oversimplifying a problem can lead to inaccurate conclusions. We need to use exactness and care in these matters. We need to be mindful of margins of error and approximations. We need to be careful how we mix similar but not identical measures. For example: 476 yards + 33 meters is not equal to 509 yards, neither is 476 shanim + 33 sh’not equal to 509 shanim.

To demonstrate a more excellent and exact approach let’s suppose that king Mosiah reigned about 32.62 years in the land. The scripture says that Mosiah died “in the thirty and third year of his reign, being sixty and three year old; making in the whole five hundred and nine years from the time Lehi left Jerusalem.” (Mosiah 29:46) If Mosiah reigned ~32.62 Promised Land years, this of course satisfies the scriptural requirement that he died “in the thirty third year of his reign…” But how many prophetic journey “years” elapsed during Mosiah’s ~32.62 year reign in the land? The answer is about 33.1 journey “years”. Here is how this was calculated:

(365.242/360) x 32.62 ≈ 33.1 journey “years”.

So the passage of about 32.62 years in the land corresponded to the passage of about 33.1 prophetic “years” of the type measured by Lehi during his journey. Can this fit the other scriptural requirements? Let’s see:

Suppose 475.5 journey years had passed when Mosiah began to reign. ^[2] This arguably satisfies the requirement that it was “in the whole, about four hundred and seventy-six years from the time that Lehi left Jerusalem” when Mosiah began to reign. (Mosiah 6:4) When Mosiah passed away, how many journey “years” would have elapsed (from Lehi’s departure)?

The answer is 475.5 + 33.1 about 508.6 journey years, or as the scripture says: “making in the whole, five hundred and nine years from the time Lehi left Jerusalem.” (Mosiah 29:46)

It is unlikely that Mosiah passed away precisely on the anniversary of Lehi’s departure. Mormon’s expression “making in the whole” indicates some kind of rounding process. It is likely that he perceived 508.9, 508.8, 508.7, or 508.6 as “making in the whole” 509.

Time from Lehi’s departure is never expressed in months because a 360 day “year” is not exactly divisible by the lunar period. Nephite sh’not, on the other hand, are composed of months - true lunar cycles. (E.g. Alma 14:23; 16:1)

It is clear that Mormon did not arrive at 509 “years” by mixing units in over simplified addition:

476 + 33 = 509

For one thing, Mosiah son of Benjamin did not reign exactly 33 years.

If Mosiah was 30.39 Israelite years old when he started to reign, “in the thirtieth year of his age”, he would have been about 30.39 + 32.62 or about 63.01 Israelite years old when he died; or to put it as simply as scripture does: “sixty and three years old” when he died. Given such information b₁ can be estimated from equation (1), but we don't need to do this here. Let’s continue.

Some have gotten the impression that king Mosiah’s reign ended and then the reign of the judges commenced. This isn’t quite correct! King Mosiah was alive when the first year of the judges commenced. (Alma 17:6)

The expressions “year of the reign of the judges”, and “year of the judges” are synonymous. (Alma 16:1, 9; 53:23; 54:1)

Scripture indicates that the last days of Mosiah’s reign and the commencement of the reign of the judges were not mutually exclusive. (Mosiah 29:11) They overlapped. (Mosiah 29:39-41) The reign of the elected judges was commenced at the request of king Mosiah. It was his laws, the laws of his fathers and of God, that the judges were obliged to enforce in the land. (Alma 1:1, 14; 11:1, 4; 27:9) It was king Mosiah who caused that the people should be governed by their own voice. (Alma 10:19)

It is true that the death of Mosiah son of Benjamin “ended the reign of the kings over the people of Nephi”. (Mosiah 29:47) He said he would be their king the remainder of his days; but before Mosiah died, judges were appointed and put in office “to rule”. (Mosiah 29:11, 30, 41-47) It is clear that “the reign of the judges” actually commenced before the death of Mosiah, (Mosiah 29:44-47) and that Mosiah died sometime in the first year of the judges. (Alma 1:1-2) Illness could have incapacitated Mosiah in his final days.

Scripture does not tell us the month Mosiah died in. It appears he died before the trial of the murderer Nehor, which we only know occurred sometime in the first year of the judges. (Alma 1:1-2)

Again, oversimplifying the facts can lead to dubious conclusions. Consider for instance the following facts:

·      The LORD told all Israel when the year was to begin.

·       Zedekiah's first regnal year started at the time designated as the first of the year.

·       Lehi left Jerusalem in the first year of Zedekiah's reign.

·       Mosiah died ~509 years after Lehi's departure.

·       The 92^nd year of the judges (91 years after the start of the first year) started ~600 years from Lehi's departure. The 92^nd year is the year of the Savior's birth.  

509 + 91 = 600

So, can we conclude that Mosiah died on an anniversary of Lehi’s departure, which happened to be the start of the year - the first year of the reign of the judges?

No - such a conclusion ignores the fact that Mosiah died after the commencement of the reign of the judges. It was not the start of the reign of the judges that scripture says happened about 509 “years” from Lehi’s departure, it was the passing of Mosiah. His death came to pass after the commencement of the reign of the judges. (Mosiah 29:44-47, Alma 17:6) The Nephite (Israelite) year in which the judges came to power started before the sons of Mosiah went up to the land of Nephi. (Mosiah 28:9-10; 29:1-3 Alma 17:6) The year did not start with the death of king Mosiah, or with the reign of the judges. The year started at the appointed time set by the LORD in Torah. (Exodus 12:1-3; 13:4)

The fact that Mosiah died about “five hundred and nine years from the time Lehi left Jerusalem”, and that the 92^nd year of the judges commenced about “six hundred years from the time Lehi left Jerusalem” (3 Nephi 1:1) fits the fact that Mosiah passed away in the first year of the reign of the judges. (Mosiah 29:44-47, Alma 1:1; 17:6)

Care must be taken in comparing years of reign and “years” from Lehi’s departure. Even though both are translated “years”, comparing sh’not and shanim is again like comparing meters and yards. 509 shanim + 91 sh’not is not equal to 600 shanim! The values need to be properly converted before operations are performed.

The reign of the judges was counted in ordinal years: 1^st, 2^nd, 3^rd ... In other words, there was no year zero starting the reign of the judges. The reign of the judges commenced with year one. The first year of the judges was the year in which the reign of the judges commenced, but this does not mean that the reign of the judges commenced exactly at the start of the year. We know in fact that the sons of Mosiah took “leave of their father, Mosiah, in the first year of the judges”. (Alma 17:6) Therefore the sons of Mosiah departed to the land of Nephi, the reign of the judges commenced, Alma the elder and Mosiah son of Benjamin passed away, and Nehor was tried, all in the first year of the judges.

“Years” from the Jerusalem departure are not ordinal but cardinal numbers. Time zero was at the start of the journey. Relating years of the judges to Lehi’s prophetic “years” requires another linear function similar to the one relating king Mosiah’s years of reign to “years” from Lehi’s departure.

Let ש₂ represent ordinal years of the reign of the judges in the land, commencing with year one (ש₂ = 1). Then:

(3)     ש₀  ≈  m ש₂  +  b₂

Again m is (365.242/360), and b₂ is the new intercept to be determined.  

King Mosiah could have died in the first year of the reign of the judges near 1 + .65 = ש₂, which is about eight months into the first year of the reign of the judges. This fits the time window of Mosiah 29:44-47 and Alma 1:1-2.

We can solve for the intercept b₂ by rearranging equation (3) - like this:

(4)     b₂  ≈  ש₀  -  m ש₂  

b₂ turns out to be about 506.92 journey “years”. Here is how it was computed:

b₂  ≈  508.6 – (365.242/360) x 1.65 ≈ 506.92 journey “years”. 

With the intercept b₂ computed based on a possible date of king Mosiah’s death, we can estimate the prophetic “years” from Lehi’s departure at the end of the 91^st year, start of the 92^nd year of the reign of the judges. We use equation (3) to do this, plugging in the value of b₂ which we just computed. We find that the commencement of the 92^nd year of the judges in the land corresponded to about 600.26 prophetic “years”. Here is how this was computed:

(365.242/360) x 92 + 506.92 ≈ 600.26 prophetic “years”, or, as scripture says, “six hundred years from the time Lehi left Jerusalem.” (3 Nephi 1:1)

The ancient Israelite year always started in the spring of the Northern Hemisphere. This was a directive given to all Israel. (Exodus 12:1-3) As long as we are consistent, we may let the Israelite year in the calculation above, be at its latest in the spring. The Hebrew year could have commenced a month earlier (~30 days earlier) in the spring. The position of the Hebrew month in its season can shift by about 30 days. This makes a difference in the decimal of about 30/365.242 ≈ .082 Promised Land years. We can use equation (2) to estimate how much this would affect the prophetic years or shanim. We find the decimal is affected by as much as .083 journey “year”. So, had the first of the Hebrew year started a month earlier, the start of the 92^nd year of the judges would have been about 600.18 prophetic shanim from the time Lehi left Jerusalem.

And some said, “Behold, the time is past, for the words to be fulfilled …” concerning the coming of Messiah. (3 Nephi 1:5) But their doubt was premature - the prophecy was soon fulfilled!

Keep in mind that the Israelite Promised Land year could be a minimum of about 29.5 x 12 = 354 days. The Israelite year could occasionally be a maximum of about 384 days. Over a long time, the average Promised Land year would effectively work out to be about 365.242 days per year. But because the ancient Israelite year is based on agriculture (i.e. the “aviv” of barley), in theory, weather and climate vicissitudes could lead to a string of shorter 12 month years. Over crucial intervals of time in the above calculations, it is possible that the average number of days per “year” could have been less than 365. This means that the decimal after the 600 prophetic “year” could be even less.

By calculation, we have found that the end of the 91^st year of the judges corresponds to about 600.18 “years from the time that Lehi left Jerusalem”. How big of a margin of error accompanies the 600 year prophetic estimate? Does scripture give us any indication? Is a margin of .18 of a journey “year” acceptable?

The English translation of the Book of Mormon never says, …from the day Lehi left Jerusalem, but rather, “from the time …” Nephi in fact notes the passing of thirty years “from the time we left Jerusalem.” (2 Nephi 5:28) Did Nephi have his wife and Zoram in mind when he wrote “we”? (2 Nephi 5:6) As long as his sons were at Jerusalem, did Lehi consider himself completely out of the city?

3 Nephi 1:2 mentions: “…all those things which had been kept sacred from the departure of Lehi out of Jerusalem.” The sacred things referred to included the plates of brass and the ball or director. Lehi’s departure out of Jerusalem apparently encompassed the time when his family acquired the sacred records and the director. Evidently, Lehi was only in the process of departing Jerusalem until he had “fulfilled all the commandments of the Lord”, concerning the records and his sons. (1 Nephi 16:8) At that point, Lehi was commanded “that on the morrow he should take his journey into the wilderness.” (1 Nephi 16:9) It was then he was given a “round ball of curious workmanship…” that “pointed the way… into the wilderness.” (1 Nephi 16:10)  Preparations, travel days, impediments and delays all considered, “the departure of Lehi out of Jerusalem” could have had a temporal margin of several weeks if not months.  The duration of .18 of a journey “year” is roughly equivalent to a couple of month’s time.

Continuing with scripture and calculations:

The passing away of the 99^th year of the judges roughly corresponded to about 608.38 prophetic “years”. Here is how this was computed:

(365.242/360) x 100 + 506.92 ≈ 608.38 prophetic “years” from the time Lehi left Jerusalem. (3 Nephi 2:4) About 608.29 prophetic shanim if the 101^st year of the judges started a month earlier.

“And also a hundred years had passed away since the days of Mosiah, who was king over the people of the Nephites.” (3 Nephi 2:5)

The expression, “since the days of...” (מִימֵי) is not numerically precise. It doesn’t exactly mean “since the death of...”. See, for instance, how this expression is used in Ezra 4:2; 9:7, Nehemiah 8:17, Alma 40:18; 50:23, Helaman 8:19, 3 Nephi 24:7, Ether 1:4 etc.

The passing of a hundred years “since the days of Mosiah” (3 Nephi 2:5) connotes a range of days, not a precise date. If we argue that it means from his death, this would suggest about 610.05 prophetic “years” from the time Lehi left Jerusalem. Here is how this is estimated:

(365.242/360) x (100 + 1.65) + 506.92 ≈ 610.05 prophetic “years” measured from the time Lehi left Jerusalem. About 609.97 shanim, if the 101^st year started a month earlier.

But the words, “since the days of Mosiah, who was king over the people of the Nephites” could simply be another way of saying, from about the first year of the reign of the judges (which included the last days of Mosiah), this works out to be about 609.39 journey “years” from the time Lehi left Jerusalem. Here is how to calculate this:

(365.242/360) x 101 + 506.92 ≈ 609.39 journey “years” from the time Lehi left Jerusalem. About 609.31 shanim, if the 101^st year started a month earlier. In other words about “six hundred and nine years … since Lehi left Jerusalem.” (3 Nephi 2:6)

But we may also estimate the date passed the 99^th year of the judges, that more precisely correlated with 609 shanim, this may in fact be closer to the date 3 Nephi 2:5 is referring to. The date is about 100.61 in the 100^th year of the judges. Here is how to compute it using equation (3):

(609 - b₂)/m  ≈  100.61 in the 100^th year of the judges.

This date was 99.61 years from the commencement of the reign of the judges (which started year 1). 100 Israelite years before this date in the 100^th year of the judges, definitely reached into the “days of Mosiah”. We assume here that the 100^th year started at its latest in the spring. Had the year commenced a month earlier, the estimate would be closer to 99.7, or almost 100 years from the start of the reign of the judges.

It is curious that in 3 Nephi 2:5, Mormon chose to use the less specific phrase “since the days of Mosiah...” instead of referencing the year of the judges as he did in the verses before. Perhaps he was intentionally trying to match sh’not with the passing of “six hundred and nine” shanim from Lehi's departure.

This brings up an important point on the accuracy of the above estimates: The above estimates are based on the long-term average of 365.242 days per Promised Land year. It is likely that the nine years starting from the year of the sign consisted of seven 354 day years and two 383.5 day years. This yields an average of about 360.56 days per year. ^[3]