On Easter Sunday, 3 April 1836, the Savior, Moses, Elias, and Elijah appeared in succession in the Kirtland Temple and restored priesthood keys required for the dispensation of the fulness of times. (See D&C 110.) Elijah’s coming had been prophesied more than twenty-two centuries earlier by Malachi. (See Mal. 4:5; D&C 110:14.)
This article reviews the importance of that restoration and suggests that it occurred on a day chosen in part because of its symbolic significance. To help us appreciate this symbolism, it will be shown that even the timing of the Lord’s death and resurrection was foreshadowed in the Passover ceremony. Then the return of Elijah, which the Jews have long anticipated at Passover, will be discussed, as well as the symbolism of the day Elijah returned in 1836.
The reader should keep in mind that the topics addressed in this article are complex, and that some of the evidence employed is by its nature inexact; nevertheless, the reader may well find the proposed conclusions to be of serious interest. (See note1for further discussion on the nature of the evidence dealt with in this article.)
In Part 1 it was proposed that the Savior’s resurrection occurred on the Sunday after Passover, 16 Nisan, or 3 April A.D. 33 on our Gregorian calendar.2 But the relationship of his resurrection to the Jewish Passover is much more than just a coincidence of dates.
The Lord instituted the Passover celebration at the time of the exodus of the Israelites from Egypt, to commemorate their release from slavery after the angel of death slew the firstborn of Egypt but “passed over” the Israelite homes. (See Ex. 12.) However, as the symbolism of the Passover is reviewed, it will be clear that the Passover ceremony is not only symbolic of the redemption of Israel from bondage, it also was in similitude of the redemption of mankind from death and sin by the Lamb of God.
The prophets taught that the ordinances of the law of Moses (such as Passover) were symbolic of things to come. For example, Abinadi explained that “there was a law given them [the children of Israel], yea, a law of performances and ordinances, … all these things were types of things to come.” (Mosiah 13:30–31.) He summarized his powerful discourse, which condemned the wicked priests for not teaching the prophetic nature of the law of Moses, with the following closing statement: “Therefore, if ye teach the law of Moses, also teach that it is a shadow of those things which are to come—Teach them that redemption cometh through Christ the Lord.” (Mosiah 16:14–15; see also Mosiah 13:30–33.)
How was the annual Passover ceremony a shadow of the redemption that would come through Christ? The Passover ceremony will now be reviewed to see how it symbolized not only the elements of the Atonement, but also their precise timing. (See “Calendar” and “Feasts” in the Bible Dictionary, LDS edition.)
The Passover feast centered on the paschal lamb, which was a sacrificial lamb, a male without blemish and with no broken bone, even after death. (See Ex. 12:5, 46.) Likewise, Jesus was the “Passover,” the “Lamb of God” (1 Cor. 5:7; John 1:29), a male without blemish and with no broken bone, even after death (John 19:36). He was the Firstborn of God in the premortal existence (D&C 93:21), sanctified in the flesh as were the firstborn of Israel (Ex. 12:23–24), and slain even as were the firstborn of Egypt (Ex. 12:29).
The Passover lamb was to be chosen on 10 Nisan, the tenth day of the Jewish lunar month Nisan. It was to be killed by “the whole assembly of the congregation of Israel” on 14 Nisan (Ex. 12:6), which was usually the day of the first full moon of spring. Jewish sources state that the lamb was sacrificed between 3:00 and 5:00 P.M. on that day.3
Jesus, too, was “chosen” on 10 Nisan4 at his triumphal entry into Jerusalem, when he was hailed as the Messiah (see Matt. 21:1–9; Mark 11:1–11; Luke 19:37–40; John 12:12–16), which had been prophesied by Zechariah (Zech. 9:9). The multitude who had assembled in Jerusalem for Passover later consented to his death when they “all” cried out on 14 Nisan, “Let him be crucified.” (Matt. 27:20–23.) The Lamb of God died about 3:00 P.M. (Matt. 27:46) on the day of preparation for Passover (John 19:14), 14 Nisan, just when the paschal lambs were also being slain.
Of course, at the triumphal entry the multitude did not understand that they were choosing the Lamb of God to sacrifice, but believed they were choosing a king (Luke 19:38) whom they expected to liberate them from Roman rule. And at the Crucifixion they were unaware that they were sacrificing the Lamb of God, but believed they were slaying an imposter who could not even save his own life. (Matt. 27:41–44.)
The preparation of the lamb for the feast had to be hurriedly completed before sunset, after which would begin the first day of Passover, 15 Nisan, a day sanctified as a special Sabbath day. After sunset, the lamb was eaten with bitter herbs, unleavened bread, and wine. This ritualized Passover meal was also called the feast of unleavened bread; it began a week in which no leavened bread was eaten, symbolic of the haste of preparation which did not allow enough time for bread dough to rise. (Ex. 12:18–20, 34, 39; Lev. 23:6–8.)
Likewise, the body of Jesus had to be hurriedly prepared for burial before the sunset would commence the Sabbath, which would be a “high day” (John 19:31) because it was not only Saturday, the weekly Sabbath, but also 15 Nisan, the first day of Passover.
It was on 15 Nisan, after the slaying of the firstborn, that Pharaoh declared liberty to the captive Israelites. After their long period of bondage in Egypt, it must have been a day of great rejoicing. One reason that 15 Nisan was sanctified as an annual feast day was to commemorate that day on which the Lord brought Israel out of bondage and released them from the chains of slavery. (See Ex. 12:14–17, 29–31; Ex. 13:3, 14–15.)
Similarly, on 15 Nisan A.D. 33, the Passover feast day, the Savior declared liberty to the captives in the spirit prison after their long period of bondage. (See D&C 138:18, 31, 42.) Before the Savior arrived, they had been “assembled awaiting the advent of the Son of God into the spirit world, to declare their redemption from the bands of death.” In fact, they were already “rejoicing in the hour of their deliverance from the chains of death.” (D&C 138:16, 18.) The fact that they were assembled, rejoicing in the hour of their deliverance, suggests that they expected his arrival on the Passover feast day, the day of liberation.
The law of Moses states that “on the morrow after the sabbath” of Passover, the priest should wave before the Lord a sheaf of the firstfruits of the harvest.5 (See Lev. 23:10–12.) On Easter Sunday, 16 Nisan, the morning after the Jewish Sabbath,6 the Savior, through his resurrection, became “the firstfruits of them that slept.” (1 Cor. 15:20, 36–38.) Jesus had already taught that he was like a kernel of grain which must abide alone until it dies in the ground, whereupon it can bring forth much fruit. (See John 12:23–24.) Lehi also explained that the Savior, “being the first that should rise … is the firstfruits unto God, inasmuch as he shall make intercession for all the children of men; and they that believe in him shall be saved.” (2 Ne. 2:8–9.)
Thus, the carefully prescribed elements of the Passover ceremony precisely foreshadowed both the events of the Atonement and the time each would occur. The annual sacrifice of the paschal lamb on 14 Nisan was not only in remembrance of the Israelites’ having been saved by the blood of the lamb on the houses in Egypt (Ex. 12:13), it was also anticipating the 14 Nisan when the great sacrifice of the Lamb of God would occur. The feast on 15 Nisan celebrated not only the liberation of the captives of Egypt; that day would also be the time of even more rejoicing when the Savior would declare liberation to the captives in the spirit prison. And the third day, 16 Nisan, was not only the time when the firstfruits of the harvest of barley were presented to the Lord, it was also the glorious day of the Resurrection—the firstfruits of the harvest of souls.
Table 1 summarizes these findings, including the dates on our Gregorian calendar, according to the chronology proposed in Part 1 of this series.
Table 1. Correspondence of the Atonement to the Passover
Event in Savior’s Life
Mon, 28 Mar
Passover lamb chosen
Messiah chosen at Triumphal Entry
Fri, 1 Apr
Sacrifice of Passover lamb
Sacrifice of the Lamb of God
Sat, 2 Apr
Feast commemorating liberation of captives from Egypt
Liberation preached to captives in spirit prison
Sun, 3 Apr
Firstfruits of the harvest presented to the Lord
Firstfruits of the Resurrection come forth
When it is thus understood how the Passover ceremony of the law of Moses was fulfilled in the resurrection of Christ, one finds further confirmation of the proposed Resurrection date in what is termed an “argument from typology.” For example, the fact that the law of Moses specifically required the lamb to be sacrificed on 14 Nisan argues against a 15 Nisan Crucifixion (a possibility discussed in Part 1). Moreover, when the symbolism of the offering of the firstfruits on the morning after the Jewish Sabbath is understood to symbolize the resurrection of the Savior, then it becomes an indication that the first Easter morning should also have occurred at the same time.6
The importance of the Savior’s resurrection occurring on Sunday was emphasized when the sanctified Sabbath day was changed from Saturday, the seventh day, symbolic of the day of rest from the labor of the Creation (Ex. 20:11), to Sunday, the Lord’s Day (Acts 20:7; D&C 59:12), the glorious day of the Savior’s resurrection.
The Easter story has two main parts: the Savior’s suffering and his triumph. The emblems of the sacrament remind us of his suffering, both in body and in spirit. (See D&C 19:18; D&C 20:75–79.) The Sabbath was changed to Sunday as a reminder of the day of triumph, the day death was conquered. In a sense, one celebrates Easter every Sunday by partaking of the sacrament.
Thus, it is clear that the Lord uses symbols to remind his people of the key points of the Atonement, even of the day it was completed. The day of Jesus’ resurrection was important enough to commemorate beforehand in the Passover ceremony and also to celebrate afterward by changing the Sabbath to Sunday.
Now the importance of another Easter event, the return of Elijah, will be reviewed, and then the significance of the date it occurred will be discussed.
The closing words of the Old Testament contain Malachi’s promise that Elijah the prophet would be sent before the Messiah to fulfill an important mission:
“Behold, I will send you Elijah the prophet before the coming of the great and dreadful day of the Lord.
“And he shall turn the heart of the fathers to the children, and the heart of the children to their fathers, lest I come and smite the earth with a curse.” (Mal. 4:5–6.)
Malachi’s words were considered so important that the Savior gave to the Nephites all of chapters 3 and 4 of Malachi [Mal. 3, 4], which end with this prophecy of Elijah’s return. After commanding them to write the words (3 Ne. 24:1), he explained, “These scriptures, which ye had not with you, the Father commanded that I should give unto you; for it was wisdom that they should be given unto future generations.” (3 Ne. 26:2.)
Clearly, Elijah’s return would be an important event in the restoration that would precede the Savior’s second coming. The first prophecy that Moroni quoted to Joseph Smith was the prophecy of Malachi (JS—H 1:36–39), with the final words modified in a way that clarifies the purpose of Elijah’s return. He would “reveal unto you the priesthood,” to “plant in the hearts of the children the promises made to the fathers,” and to turn the hearts of the children to their fathers. (D&C 2:1–2.)
The promise of Elijah, taught by the scribes in Jesus’ day, is still remembered by the Jewish people every year at Passover. A special place is set for him, with a cup of wine. At a prescribed time during the meal, the door is opened for him to enter.
The origin of the tradition that Elijah would return at Passover seems to have been lost in antiquity. It has been suggested that Elijah’s return was associated with Passover, the feast commemorating the redemption of Israel, because it would herald the coming of the Messiah, the Redeemer of Israel.7
Whatever the origin of the association of Elijah with Passover, the tradition was proved correct when Elijah did return at Passover in 1836. However, he did not return at the Passover meal, when the cup was offered on the evening of Friday, April 1.8 Instead, he returned on Easter Sunday, the second day of Passover, the day of the presentation of the firstfruits of the harvest.
The long-awaited return of Elijah occurred in the Kirtland Temple on Easter Sunday, 16 Nisan, 3 April 1836. First the Savior appeared, followed by Moses, then Elias, and finally Elijah.
Moses restored the “keys of the gathering of Israel,” one of the necessary preparations for the Second Coming. These include the keys to gather scattered Israel from the four quarters of the earth and to lead the Ten Tribes from the land of the north. (D&C 110:11.)
Elias “committed the dispensation of the gospel of Abraham, saying that in us and our seed all generations after us should be blessed.” (D&C 110:12.)
Elijah restored “the power to hold the key of the revelations, ordinances, oracles, powers and endowments of the fulness of the Melchizedek Priesthood and of the kingdom of God on the earth; and to receive, obtain, and perform all the ordinances belonging to the kingdom of God, even unto the turning of the hearts of the fathers unto the children, and the hearts of the children unto the fathers, even those who are in heaven.”9
The Prophet Joseph Smith explained that “the spirit of Elias is first, Elijah second, and Messiah last. Elias is a forerunner to prepare the way, and the spirit and power of Elijah is to come after, holding the keys of power, building the Temple to the capstone, placing the seals of the Melchizedek Priesthood upon the house of Israel, and making all things ready; then Messiah comes to His Temple, which is last of all.”10
Thus, the coming of Elijah on 3 April 1836 was to occur after forerunners had returned in the spirit of Elias to prepare the way. (See D&C 27:6–7; D&C 128:20–21.) At his return, Elijah declared: “Therefore, the keys of this dispensation are committed into your hands; and by this ye may know that the great and dreadful day of the Lord is near, even at the doors.” (D&C 110:16.) With the keys of the dispensation of the fulness of times (D&C 112:30) restored, the Church would then “build up the kingdom before the coming of the great day of the Lord.”11
Now a further witness from astronomy will be presented, showing that the Easter of Elijah’s return was a most remarkable anniversary of the day of the Savior’s resurrection.
Ancient prophets had revelations concerning the use of astronomy for reckoning time. Abraham, for example, was given to know the “set times” of the earth, moon, and sun, and then was shown that these “lights in the expanse of the heaven” were to be “for signs and for seasons, and for days and for years.” (Abr. 3:6; Abr. 4:14.) In obedience to the Lord’s direction, Abraham then taught these principles of astronomy to the Egyptians (Abr. 3:15; see also Facsimile 3), who in turn may have taught them to Moses, who was raised as Pharoah’s grandson (Ex. 2:10). Moses also received revelations mentioning the use of the sun and moon to reckon time (Moses 2:14), which became very important in determining sacred days according to the law of Moses (see Lev. 23).
The Jewish lunisolar calendar uses three of the cycles that were revealed to Abraham (see Abr. 3:1–18): the day is reckoned principally by the earth’s rotation, the month by the moon’s phases, and the year by the sun’s apparent annual motion.
Even in our day, the Lord has promised that “all the days of their days, months, and years, and all their glories, laws, and set times, shall be revealed in the days of the dispensation of the fulness of times.” (D&C 121:31.)
As an astronomer who has studied the lunisolar calendar, I was intrigued by Elijah’s return occurring not only during Passover week, as anticipated by the Jews, but also on an Easter Sunday that was calendrically similar to the proposed date of the Savior’s resurrection, being both April 3 on the Gregorian calendar and 16 Nisan on the Hebrew calendar.
Was that merely a calendrical coincidence? Or could the timing of Elijah’s return have been purposely chosen to correspond to some special Passover in accordance with Jewish tradition? Pursuing these types of questions led me to discover an interval of time that is so remarkable in an astronomical sense that it seems to constitute evidence that the timing of Elijah’s return was carefully chosen.
Easter is always on Sunday, usually the first one following Passover, a calendrical choice that commemorates the Savior’s resurrection on Sunday. It can also serve as a reminder that he was crucified at the Passover, the ceremony foreshadowing his great sacrifice. Because of the relationship of Passover to the lunisolar calendar, Easter is usually the first Sunday after the first full moon on or after the spring equinox. Thus, the date of Easter varies from year to year, occurring between March 22 and April 25.
Accordingly, only about one Easter in thirty will fall on any particular day during that period, such as April 3. Moreover, not all Easters fall on the same day of the Judean month, but usually between 15 Nisan and 21 Nisan.
So, how often does Easter Sunday occur on both April 3 and 16 Nisan, as it did in A.D. 33? It happens less than once every century, on the average. The year 1836 was the only such occurrence in the nineteenth century.
Interestingly, the accuracy of the calendrical alignment between A.D. 33 and 1836 is even more precise than to the very day. To understand this added precision, a new concept called a “realignment interval” will be defined and applied to the lunisolar calendar.
Lunisolar Calendar Realignment Interval
When can Easter Sunday occur on 16 Nisan on the Jewish calendar and also on April 3 on our Gregorian calendar, which is based on the solar year? For such an occurrence, the interval between that Easter and Sunday, 16 Nisan, 3 April A.D. 33 would have to equal a whole number of weeks, and of lunar months, and of solar years.12 Accordingly, a “realignment interval” for the Jewish calendar is defined as a period of time such that no shorter period is so nearly an exact number of days, weeks, months, and years. (See “Realignment Intervals” sidebar for details.)
To the very day, the Easter of 1836 completed a Jewish calendar realignment interval of 1,803 years since the Easter of A.D. 33.13 This fact has two consequences. First, the Jewish calendar would begin to repeat for several years.14 Secondly, it means that the Easter of 1836 was calendrically the most similar in history to the Easter of A.D. 33. And if the earth’s orbit continues unchanged, that Easter should retain this distinction for another three thousand years, when a better realignment interval is due.
From an astronomer’s point of view, this is no small coincidence. This result seems to clearly support the conclusion that it was not a matter of chance that Elijah’s return occurred on an Easter Sunday that was also 3 April and 16 Nisan, which is calendrically the same as the proposed date of the Resurrection. But before discussing some possible reasons for such an occurrence, let us discuss a second astronomical aspect of the timing of Elijah’s return.
A Saros Century
The interval of 658,532 days15 (1,803 years) between 3 April A.D. 33 and 3 April 1836 is also impressive for an entirely different astronomical reason than that discussed above. To the very day, it is equal to 100 saros periods of 6,585.321 days each. The saros is a period of 18.03 years known to astronomers as the interval in which solar or lunar eclipses often repeat.16 (See “The Saros” sidebar for details.)
It should be emphasized that the fact that the same period of time (1,803 years) can be equal both to a lunisolar calendar realignment interval and to 100 saros periods is very surprising because the length of the saros is also determined by other factors.17
Is there any astronomical significance to the number 100? Yes, it turns out that 100 saros periods is the realignment interval for a saros with the solar year. That is, if one counts saros periods from the lunar eclipse that occurred on the proposed date for the Crucifixion, 1 April A.D. 33, the first time that a saros would again begin on April 1 would be in 1836.
Note, however, that the saros alignment is only sufficient for eclipses to reoccur for up to 70 saros periods; thus, eclipses do not reoccur after 100 saros periods.18 On the other hand, the orbital alignment is close enough to produce an interesting calendrical alignment. After 100 saros periods, the lunar orbit is in about the same orientation relative to the sun, which causes the Judean calendar to also begin to repeat (because it uses the actual observed lunar position rather than the average position.)19 Calculations indicate that the Easter of 1836 was also calendrically best on the Judean observational lunisolar calendar.20
In summary, a period of 1,803 years (658,532 days) is simultaneously two realignment intervals: (1) for the day, week, month, and year of the Jewish calendar; and (2) for the saros and the year. It seems impressive enough to merit a special name;21 perhaps it could be called a “saros century,” being 100 saros periods.
Now consider some possible reasons for such astronomical precision in the timing of Elijah’s return.
The evidence presented above suggests that the timing of Elijah’s return may have been arranged to occur on the best anniversary of Easter, calendrically speaking, in history. But for what reason?
The Lord’s possible intent in such a matter may be beyond our understanding (see Isa. 55:8–9); on the other hand, the scriptures are given to us to search for understanding, and in that spirit it may be acceptable to offer the following four possibilities.
1. Timing of the Last Dispensation. This is the dispensation of the fulness of times. When did it begin? At the First Vision? At the organization of the Church? One clue to answering this question was provided by the Prophet Joseph Smith, who taught that the sealing power of Elijah has been given in every true dispensation of the gospel (D&C 128:9), and that it “is necessary in the ushering in of the dispensation of the fulness of times, which is now beginning to usher in.” (D&C 128:18.)
Thus, apparently this dispensation could not have fully begun before 3 April 1836, when the keys of Elijah were restored. But by July 1837 the dispensation apparently was in progress, when the Lord called it “the dispensation of the fulness of times” and referred to “the keys of the dispensation” which had been restored. (D&C 112:30–32.) Finally, Elijah’s own declaration seems to favor the significance of the 3 April 1836 date, for it was then that he declared, “The keys of this dispensation are committed into your hands.” (D&C 110:16.)
But why would the bestowal of the keys of the dispensation of the fulness of times have been timed to coincide with a special anniversary of the Resurrection? One possible reason is that one use of the phrase “fulness of time” referred to the time when the law of Moses would be fulfilled. Lehi prophesied that “in the fulness of time he [the Redeemer] cometh to bring salvation unto men.” (2 Ne. 2:3.) Paul clarified the meaning: “When the fulness of time was come, God sent forth his Son to redeem them that were under the law.” (Gal. 4:4–5.) Thus, the “fulness of time” apparently referred to the time that man would be redeemed, which was completed at the resurrection of the Redeemer.
At his return, Elijah stated that “the time has fully come” for Malachi’s prophecy to be fulfilled (D&C 110:14), suggesting that the prophecy of Elijah’s return was to be fulfilled at a specified time. Perhaps he also implied that the time had fully come to begin the fulness of times.
Thus, on Sunday, 3 April 1836, apparently the time had fully come to open the dispensation of the fulness of times on a special anniversary of the fulness of time of the Resurrection.
2. Timing of the “Elijah Period.” As discussed earlier, the Prophet Joseph Smith taught that “the spirit of Elias is first, Elijah second, and Messiah last.” This teaching suggests three distinct periods in Church history.
Perhaps 3 April 1836 can be thought of as the close of the “Elias period” or preparatory phase of Church history, when finally all the forerunners had restored their keys in the spirit of Elias. (See D&C 27:5–13; D&C 128:20–21.) This period could have been closed when Elias himself, perhaps the same Elias who holds the keys of the restoration of all things (D&C 27:6), returned immediately before Elijah.
Then the next period could have commenced with the long-awaited advent of Elijah’s return. The Church would then enter into an era of temple work and building up the kingdom, having had all of the preparatory keys restored. The “Elijah period” would then end with the coming of the great day of the Lord.
3. Restoration of the Temple. The Lord used the symbolism of comparing his body to the temple. (John 2:21.) It seems very fitting that the restoration of the power and glory of the temple should occur on such a noteworthy anniversary of the restoration of the body of the Savior to power and glory. Note that the words resurrection and restoration are used interchangeably in the Book of Mormon (as in Alma 40–41), which is not surprising because resurrection is a type of restoration.
Further, one can note the calendrical similarity of the events of the week prior to April 3, according to the chronology presented in Part 1. On Sunday, 27 March A.D. 33, the body of Jesus was anointed (“dedicated”?) for burial. (John 12:1–7.) Similarly, the Kirtland Temple was dedicated on Sunday, 27 March 1836. (D&C 109.) Moreover, during the week following both of these dedications, the ordinance of the washing of feet was introduced and the sacrament of the Lord’s supper was observed. (See History of the Church, 2:410–40.)
4. Body of the Church Restored. The Lord’s church has also been compared to his physical body. After discussing the interdependence of various members of the physical body, Paul concluded, “Now ye are the body of Christ,” and explained that all positions in the Church are important. (1 Cor. 12:12–31.)
The organization of the Lord’s church in the latter days occurred on 6 April 1830. Apparently, this “birth” of the ecclesiastical “body of Christ” occurred on the anniversary of the birth of his physical body, 6 April 1 B.C. Thus, a correspondence is suggested between the birth of the Savior and the birth of his church.
It is proposed that on Easter Sunday, 16 Nisan, 3 April A.D. 33, the physical body of Christ was restored, clothed with a fulness of power and glory. (See Alma 40:23.) On Easter Sunday, 16 Nisan, 3 April A.D. 1836, the ecclesiastical body of Christ was restored, clothed with a fulness of priesthood authority. Thus, a correspondence is suggested between the restoration of the body of the Savior to a fulness of power and the restoration of the body of the Church to the fulness of the Melchizedek Priesthood.
This article has attempted to show that the dates of the principal events in the Savior’s life and the date of Elijah’s return in this last dispensation are remarkably rich in significance. The restoration of the keys of this dispensation was an extremely important event which occurred on a very special anniversary of the proposed resurrection date for our Lord and Savior, Jesus Christ. On Easter, may we not only remember the restoration of the Savior’s physical body, but also the restoration of the fulness of the priesthood to the body of his church.
To understand the concept of a “realignment interval,” consider a wristwatch. (Figure 1.) It has a second hand, a minute hand, and an hour hand to keep track of three different time intervals. The starting point of the day occurs when all three hands point exactly straight up. A realignment interval for the watch is completed when all three hands again point straight up, that is, after exactly twelve hours.
Realigning the hands of a watch is simple because there are an exact number of seconds in a minute and an exact number of minutes in an hour. Thus, the first realignment interval encountered is a perfect lineup, and there is no reason to search for more accurate intervals.
A calendar can be thought of as a clock that keeps track of longer periods or cycles of time—the sun and moon are like the hands of the clock. Note that our word “watch” (meaning clock) is the same as that formerly used to describe a time period determined by “watching” the sky (as in Matt. 24:43). A problem that arises is that sometimes the cycles do not “come out even.” For instance, the solar year, in which the seasons repeat, equals 365.2422 days rather than a whole number of days such as 365. A question fundamental in the construction of any calendar is how to align the different cycles. The solution lies in finding an interval that is approximately a whole number of all the cycles.
The problem can be represented by the device drawn in Figure 2a. The large pulley has a circumference equal to 365.2422 times that of the smaller one. If each one has an arrow painted on it that points exactly vertical, after how many revolutions will both arrows be pointing straight up again?
Because the circumference is an irrational number of days, as is the case with most astronomical periods, the two pointers never again point straight up exactly simultaneously. There are only approximate solutions; the longer one is willing to wait, the more accurately they will align.
For example, after 365 revolutions of the small wheel, the larger one almost (but not quite) finishes a rotation, so a first approximation to a year is 365 days. But after 1,461 revolutions of the small pulley, one might notice that the large one has more nearly completed exactly four turns (years). That gives an average year of 1,461 divided by 4 = 365.25 days, which is the reason we add a leap day every 4 years. Our Gregorian calendar is based on the observation that 146,097 days very nearly equal 400 years, giving an approximate year of 146,097 divided by 400 = 365.2425 days.
A realignment interval for the set of pulleys is a number of turns of the smallest one which brings all of the arrows back to the vertical point better than any smaller number of turns.
The seemingly simple problem of finding a realignment interval for several cycles is, in fact, a very difficult problem in number theory;* fortunately, however, it is easily solved with a computer by “brute force”—by simply checking every possible combination of numbers for the best fit.
For our solar calendar, 4 years is a realignment interval, whereas 400 years is not because there is at least one better solution with a smaller number of years (12,053 days divided by 33 years = 365.2424 days).
Figure 2b depicts the more complex problem of realigning the lunisolar calendar, which also includes the lunar month, the period of the moon’s phases. The modern Hebrew calendar employs a realignment interval, called the Metonic cycle, that has been known since at least five centuries before Christ: 19 years very nearly equal 235 lunar months. This means that the lunisolar calendar requires leap months as well as leap days.
Figure 2c represents the problem of realigning the Jewish calendar described in the text, also including the week as a cycle. The realignment intervals include 68, 152, 220, and 372 years. For example, in this century Easter falls on 3 April, 16 Nisan (Jewish) in the years 1904 and 1988, being 68 and 152 years after 1836, respectively. For longer realignment intervals, the variable lengths of the year and day must be considered. The realignment interval of 1,803 years discussed in the text is better than any other until 5,382 years have elapsed.
Perhaps the greatest contribution to astronomy from ancient Chaldea was the discovery of a period of 6,585 days (18.03 years) called the saros, after which eclipses might repeat.**
An eclipse occurs when the sun, moon, and earth form a straight line. Solar eclipses occur at a new moon, when the earth is in the moon’s shadow; lunar eclipses are at full moon, when the moon passes into the earth’s shadow. (See Figure 1.)
For a given series of eclipses to reoccur, three conditions need to be fulfilled:
1. The phase (full or new) of the moon must be the same, which is why similar eclipses are always separated by a whole number of lunar months of 29.53059 days.
2. The moon must be near the place where its path crosses the sun’s apparent path. The period of such crossings is 27.21222 days.
3. The moon needs to be at about the same distance from the earth in order to completely cover the sun in total solar eclipses. (The moon’s distance from the earth changes because its orbit is not circular, which makes its apparent size vary by about 10 percent.) This reoccurs in intervals of 27.55455 days.
Thus, the problem of predicting when eclipses will repeat is a question of finding a realignment interval for those three cycles. (See Figure 2.) After an eclipse, when will all three cycles again coincide? One of the very best realignment intervals is the saros of 6,585.32 days.
As discussed in the text, the return of Elijah occurred 100 saros periods after the proposed date of the Savior’s resurrection.