Defense of April Sixth

by John P. Pratt

Reprinted from "Afterwords," B.Y.U. Studies 23, No. 2 (Spring, 1983), pp. 252-254.
[Note: The following was published as a letter to the editor in response to a scathing review of the book April Sixth, by John Lefgren. Following this defense of the book is the response of the authors of the review.]
Index, Home

To the editor:

The review of John Lefgren's April Sixth by S. Kent Brown, C. Wilfred Griggs, and H. Kimball Hansen (Summer 1982) claims that Lefgren's work "abounds in unjustified assumptions, misinformation, and misunderstandings." But, on the contrary, Lefgren's book contains valid scientific research, giving new insights on the Savior's birth date. The reviewers' objections are either unfounded or irrelevant.

Lefgren states that his intent is "to show how the modern revelation concerning the significance of April 6 is in perfect harmony with other sacred writings" (p. 12). That is, he proposes that the belief that Jesus was born on 6 April 1 B.C. is consistent with all LDS scripture, but not necessarily with all secular sources. (All dates refer to our Gregorian calendar.) The reviewers claim that Lefgren also believes the "resurrection of Jesus fell on April sixth." He does not; his date for the Resurrection is 3 April A.D. 33 (p. 61).

The reviewers characterize Lefgren's methodology as "unscholarly," but he actually followed the scientific approach of testing a theory that had been proposed to explain certain observations. Lefgren observed (1) that some LDS leaders had interpreted D&C 20:1 to mean that Jesus was born on 6 April 1 B.C. and (2) that both the Bible and the Book of Mormon discuss chronological aspects of the Savior's life. His theory was that if these observations are accurate they should be self-consistent, and he tested the theory by examining every relevant scriptural reference. He found none that conflicts with a birth date of 6 April 1 B.C.

But Lefgren's greater contribution is that he also found another witness to that exact birth date. Through an impressive demonstration of interscriptural self-consistency, Lefgren shows that by beginning on a biblical crucifixion date and then counting back the number of years and days of the Savior's life from the Book of Mormon one arrives at 6 April 1 B.C., the exact birth date implied by the Doctrine and Covenants. This is new evidence for the 6 April birth date because it is not based solely on a literal interpretation of D&C 20:1.

Let me summarize the main points of his argument. Although the Bible is vague about the date of the Savior's birth, it is so precise about his death that the day Friday, 1 April A.D. 33, is indicated. Another possible date is 5 April A.D. 30, but Hoehner concludes persuasively that "the A.D. 33 date for the death of Christ best explains the evidence of both sacred and secular history."[1]

The Book of Mormon account is so precise as to suggest the exact number of years and days that the Savior lived. It describes the appearance of a sign that heralded the Savior's birth on the following day (3 Ne. 1:19) and states that time was later reckoned from that sign. It also describes a great destruction at the Savior's death on the fourth day of the thirty-fourth year (3 Ne. 8:5). Thus, if Jesus was born on the first day of the first year, he lived thirty-three Nephite years and three days.

Orson Pratt first suggested that the Savior's birth date could be calculated by starting on the better-established crucifixion date and counting back the number of years and days from the Book of Mormon (Journal of Discourses, 15:253). He proposed that the Nephite year probably had exactly 365 days as did the mesoamerican calendar and the ancient Egyptian calendar.

Having identified the fourth day of the thirty-fourth year as 1 April A.D. 33, one counts back three days more than 33 Nephite years. Because our calendar would insert eight leap days in those thirty-three years, one must count back five days less than thirty-three of our years, arriving at 6 April 1 B.C. for the birth date. (The year before A.D. 1 was 1 B.C.) It is not surprising that Lefgren interprets such impressive interscriptural accuracy in minute chronological details as evidence that Joseph Smith was a prophet.

The reviewers' principal objection seems to be that secular history "proves beyond a doubt" that Herod, who was visited by the Magi after Jesus' birth, died in 5-4 B.C. If so, Jesus must have been born about 6 B.C. rather than 1 B.C. But this objection is irrelevant to Lefgren's thesis that the scriptural sources are consistent with a 1 B.C. birth. Moreover, there is doubt about Herod's death date, which some historians still claim occurred about 1 B.C.[2] Because Lefgren was unconvinced about Herod's death date, the reviewers conclude that "April Sixth is exposed as a house built upon sand." But to me it was refreshing to see Lefgren use the scriptures as a standard to judge secular sources, rather than vice versa.

In order to correlate with our calendar, Lefgren had to choose one date from secular history. Lefgren is not especially concerned with the dispute over Herod's death date because, implicit in his choice of crucifixion date, he has anchored his chronology to secular history through the undisputed death date of Augustus Caesar, which the reviewers agree is "known almost to the minute." It is ironic that when the reviewers insist that "there exists no tolerance of at least two years" in determining the beginning of his successor's reign, they unwittingly undermine the principal argument for the A.D. 30 crucifixion date, which they presumably favor.

Lefgren notes that Luke's chronology implies that Jesus was born in 2-1 B.C. The reviewers attempt to discredit Luke's account by appealing to Tertullian because they believe he supports their theory that Jesus was born about 6 B.C. But Tertullian states, "Augustus survived, after Christ is born, fifteen years" (Finegan, p. 224). The death of Augustus in August A.D. 14 is in the fifteenth year after April, 1 B.C., so Tertullian actually agrees with Luke and Lefgren, not with the reviewers. In fact, most of the early Christian writers support a 2-1 B.C. birth date.

The reviewers criticize Lefgren's choice for the crucifixion year of A.D. 33, maintaining that Parker and Dubberstein "raise serious questions about Fotheringham's work and all but show that the Passover of A.D. 33 fell on May second." But on the contrary, Parker and Dubberstein claim their tables are based on Fotheringham's calculations.[3] They list Nisan as postponed one month in A.D. 33 on the Babylonian calendar, which intercalated years according to a fixed nineteen-year cycle. In Jerusalem, intercalation was done both by astronomical and local agricultural conditions.[4] Finegan, after examining the Parker and Dubberstein results, concludes that the A.D. 33 and A.D. 30 dates are the only possible candidates (Finegan, p. 300).

The reviewers also attack Lefgren's astronomy, but their objections are either irrelevant or based on their misunderstanding of the observational lunisolar calendar. For example, the reviewers claim that Lefgren assumes "that the sky was clear on the dates chosen" so that the thin crescent of the new moon could be seen. But the Judean court used calculations to determine the first day of the month during bad weather (Maimonides, pp. 75-77). The reviewers also claim that a twenty-eight hour old moon would be "among the earliest sightings ever recorded," whereas it would have been so commonplace as not to have even been considered marginal.[5]

The reviewers note that Lefgren's results hinge on some "unproven assumptions." True, as does all scientific theory, but if his assumptions are correct, then his result is valid. Let us then examine these assumptions.

Lefgren assumes the Nephites used a 365-day calendar as did the Egyptians and the Mesoamericans. The Jewish lunisolar calendar may seem more reasonable, but it does not fit the data: the Savior's death occurred on the fourteenth day of the lunar month (John 19:14), not the fourth day (3 Ne. 8:5). I can think of no better assumption than Lefgren's, and the reviewers offer none. Orson Pratt made the same assumption, and he cannot be accused of having "preconceived notions" because he counted back from the earlier crucifixion date and thus did not arrive at 6 April or at 1 B.C.

The scripture states the Nephites reckoned from the "time" or the "period" when the sign was given (3 Ne. 2:7-8), which Lefgren interprets to mean from the very night of the sign. Again, Orson Pratt made the same assumption, which seems justified by the wording used. The reviewers suggest an alternate assumption that they reckoned only from the year of the sign, not changing the first day of the year. Perhaps, but in that case the first day of the first year would still be 6 April 1 B.C. (Given the 365-day year), and the Savior would have been born thereafter (3 Ne. 1:1). But that contradicts the reviewers' idea that Jesus was born in 6 B.C., even using the earlier crucifixion date.

The final objection is that the belief that Jesus was born on 6 April 1 B.C. is based on D&C 20:1, which alone is inconclusive. True, but we have prophets to interpret scripture. For example, President Harold B. Lee interpreted that verse to mean that 6 April was the anniversary of the Savior's birth (Ensign, July 1973, p. 2); President Spencer W. Kimball taught likewise (Ensign, May 1980, p. 54). The reviewers instead cite an Apostle who says only that he "cannot state with finality when the natal day of the Lord Jesus actually occurred."

It should be clear from these observations that April Sixth is a far more valid book than the reviewers claim. A thesis founded on the prophets and scripture cannot be "exposed as a house built upon sand."

Dr. John P. Pratt
Astronomer with Eyring Research Institute
Provo, Utah


  1. Harold Hoehner, Chronological Aspects of the Life of Christ (Grand Rapids, Mich.: Zondervan, 1977), p. 111. See also Jack Finegan, Handbook of the Biblical Chronology (Princeton, N.J.: Princeton University Press, 1954), pp. 285-301. Both use the Julian calendar.
  2. See, for example, John Mosley, "When Was That Christmas Star?" Griffith Observer 44 (December 1980): 2-9; and John Mosley and Ernest Martin, "The Star of Bethlehem Reconsidered: An Historical Approach," The Planetarian 9 (Summer 1980): 6-9; countered by Douglas Johnson, "The Star of Bethlehem Reconsidered: A Refutation of the Mosley/Martin Historical Approach," The Planetarian 10 (First quarter 1981); 14-16.
  3. Richard A. Parker and Waldo H. Dubberstein, Babylonian Chronology 626 B.C.-A.D. 75 (Chicago: University of Chicago Press, 1942), p. 23.
  4. An excellent reference on the observational Jewish lunisolar calendar is The Code of Maimonides: Sanctification of the New Moon, trans. Solomon Gandz (New Haven, Conn.: Yale University Press, 1956).
  5. Using the equations of H. Goldstine, New and Full Moons 1001 B.C. to A.D. 1651 (Philadelphia: American Philosophical Society, 1973), I calculate the elongation in question to be over 15 degrees, which was deemed "visible" by the court (Maimonides, p. 65).


The accompanying correspondence from John Pratt concerning John C. Lefgren's work, April Sixth, has merit and has been instructive. Weaknesses, however, still persist. While others could be mentioned, we need only focus on the two notions which buttress the entire position of both Lefgren and Pratt, items which we discussed at some length in our review (BYU Studies 22 [Summer 1982]: 375-83.

I. The first key to the position adopted by Lefgren and Pratt rests on the chronometrical system supposedly employed by the people of the Book of Mormon. It is assumed by both that because the Egyptian and the Mesoamerican calendars each have 365 days, the latter must have been derived from the former by way of the Nephite time-reckoning scheme. Several difficulties immediately appear. (1) Why must the two chronometrical systems be linked? Is it not possible­even more likely­that astronomical observations made independently in each culture led to a similar calendar? (2)Why suppose that the Nephites employed the Egyptian calendar when their religious observances must have been based on the Israelite reckoning of Lehi's time? (3) As we noted in our earlier essay, the accompanying point that the Nephites counted time from the very day of the sign of Jesus' birth is but an assumption. The one clearly relevant passage is not precise enough to allow any such definitive conclusion (3 Ne. 2:5-8). (4) For purposes of establishing Jesus' birthdate, we note that had the Nephites adopted the Egyptian 365-day calendar, the first day of the year at the time of Jesus' birth would have fallen in July, not April! Simply stated, we do not know the length of the Nephite year. Period.

II. The impossibility of dating Jesus' birth in 1 B.C. arises from the date of Herod's death. For one to draw attention to a variety of astronomical possibilities or to advance arguments based on sources written more than a millennium after the time of Jesus (e.g. Maimonides) misses the point. We know how long Herod reigned and when his reign began. Historical and numismatic evidence are conclusive: Herod died in 4 B.C. Try as one might, one cannot escape this fact.

Other observations could be made, for example, concerning the chronological differences between the synoptic Gospels and John's Gospel in the accounts of Jesus' death and concerning the anachronistic arguments about how the lunar month is begun when the new crescent moon is not or can not be seen. But such would be connoisseurs' points which do not affect the fundamental position adopted by author and correspondent. The two key issues detailed briefly above, particularly the latter, in our view, stand decisively against any historical attempt to date Jesus' birth to 1 B.C.

S. Kent Brown
C. Wilfred Griggs
H. Kimball Hansen
Professors at Brigham Young University