From the beginning of history many calendar systems have been developed. To understand these ancient calendars it is necessary to relate them to the present western calendar system, the Gregorian calendar. The conversion of artificial or lunar dates into the Julian or later Gregorian calendar can be a challenge. Understanding the historical beginnings of the Gregorian calendar provides some perspective on what to expect with these early calendars.

Julius Caesar decreed the Julian calendar that began on January 1, 45 BCE. The present Gregorian calendar is identical with the Julian calendar with a few adjustments because the true solar year in not exactly 365¼ days long. In 1582 Pope Gregory XIII issued a papal bull that decreed that the day following Thursday, October 4 would be Friday, October 15. Besides dropping ten days from the calendar there was the additional requirement that three leap days in 400 years would not be observed. Thus began the Gregorian calendar, a reflection of the Julian calendar of twelve centuries earlier.1

The Christian church became involved with calendar reform to keep Easter in the spring. In 325 CE the Council of Nicaea had decreed that the observance of Easter2 would be uniform at all Christian churches. Easter was to be the first Sunday following the full moon after the Vernal Equinox, which marks the beginning of spring. In 325 CE the Vernal Equinox fell on March 21, and Easter could occur as early as March 22, but not later than April 25. At the beginning of the Julian calendar in 45 BCE the Vernal Equinox fell on March 25, but this day had regressed to March 21 by three centuries later.3 By the sixteenth century the Vernal Equinox had regressed ten more days to March 11, but the Gregorian reform returned the Vernal Equinox to March 21. The reform did not adjust to dating of the Vernal Equinox to the time of Jesus' crucifixion, which then fell about March 24. The present calendar is about three days out of alignment with the calendar of the first century CE. However, the reform stopped the calendar drift, and the calculation of Easter was to be the same as in the year 325 CE.

Easter commemorates the resurrection of Jesus several days after the Passover. The Passover is the Jewish feast that commemorates the death of the Egyptian first-born while the Lord passed over the first-born of Israel. This night before the Exodus is observed in the evening of the fourteenth day of the first Jewish month, at about full moon. The lunar month began about two weeks earlier with the new moon. At the time of Jesus' crucifixion the local lunar calendars determined the beginning of that spring month by observation of the new crescent moon. Two of three methods confirmed the exact first month: barley coming into ear, the sun entering the constellation Aries, and the day of the Vernal Equinox. The particular calendar alignment of that first Easter provides substantial clues to accurately dating the year of Jesus' crucifixion.

All the luni-solar calendars to be discussed are based on the new year beginning near the Vernal Equinox (or Autumnal Equinox). One point that is critical to comparison of the calendars will be whether the first month of the new year began closest to the Equinox, before or after, or with the first new moon following. In the determination of Easter the Church knew, or presumed, that the Jewish month of Nisan at the time of Jesus could begin before the Vernal Equinox. Since Easter can fall as early as the day after the Vernal Equinox and at a full moon, then the new moon and new year might occur up to two weeks earlier. The first Babylonian month of Nisanu during that period began with the new moon after the Vernal Equinox. This would have been approximately equal to the contemporary Jewish calendar only about half the time. This (1) relationship to the Equinox, (2) beginning the day in the morning or evening, and (3) whether the new year began in the spring or fall, will be among the main points discussed in this examination of the calendars found in Scripture and contemporary literature.

The understanding of the language4 and the interpretation5 of the first chapters of Genesis has led to a wide range of explanations. Was the creation ex nihilo and in an instant? Or did it take six calendar days before the Sabbath rest? Was each day twenty-four hours, a thousand years or an age?6 Or did the "creation" always exist and the description was allegorical?7 Did the event occur in the dim past, about 4004 BCE,8 or at the Jewish date in the fall of 3761 BCE? Such questions are mostly beyond this discussion. However, the attempts at a literal explanation have led to the establishment of the various forms of the Jewish calendar. A literal examination will be here pursued. Which interpretation is correct is less important to this discussion than the fact that the different interpretations support different calendar reckonings. From this perspective, when the Scriptures were actually recorded is secondary to when the interpretations were made.

The first day of creation began when "God said, `Let there be light,' and there was light. And God saw that the light was good; and God separated the light from the darkness. And God called the light day, and the darkness He called night. And there was evening and there was morning, one day." (Gen. 1:3-5) Darkness was the previous eternal state, with light beginning "one day,"9 and those following. Daylight followed by darkness was one day, just as in the sequence above. The translation "Evening" carries the meaning of "dusk" or "sunset" that is the end of daylight or passage of day to night. "Morning" carries the meaning of "dawn" that is the end of night or the passage of night to day. The end of "one day" is the end of light followed by the end of darkness. The days of creation consisted of daylight followed by night.

The common interpretation of the days of creation is that nighttime was followed by daylight. This is by interpreting "evening" and "morning" as the beginning, instead of the end of the day sequence (Mishna, Hullin 5:5). But, God called the light "day" and the darkness "night" in the opposite sequence. In the night/day interpretation the first period of darkness would have been "eternally" long. The "first" day, with night preceding day, would have also been eternally long. The "first" day could not have been twenty-four hours, but as long as the previous darkness plus twelve hours. During the creation Scripture does not support a twenty-four hour calendar day, with night preceding day. The first day was twenty-four hours only if day preceded night, if that were the length of a creation day.

On the fourth day of creation, "God said, `Let there be lights in the expanse of the heavens to separate the day from the night, and let them be for signs, and for seasons, and for days and years.'" (Gen. 1:14) The sun, moon and stars are for the determination of signs, seasons, days and years. There is no indication in Scripture that God gave Adam a specific calendar. God gave Adam and his descendants the sun, moon and stars to determine time. In such early days the first notice would have been the phases of the moon. The derivation of the Hebrew word for "month" is from "moon." This suggests a calendar based on lunar observation, at least during the earlier days of calendar formation. There are about twelve and a third lunar months in a solar year, and the shifting seasons could not be missed. The early method of correction of lunar months to a solar year is not known. There is no indication in Scripture when the new year might have begun, although the present Jewish calendar dates from a creation in the fall month of Tishri. One can expect that the Creation calendar was lunar, with the day beginning at sunrise; when the year began is not known.

During this early period the Egyptians used an artificial calendar which contained twelve months of thirty days and a thirteenth month of five days, or 365 days in a year. The beginning of the Egyptian calendar has been projected back to 4241 BCE, earlier than some would place the creation. This calendar was an astral calendar based on observation of the heliacal rising of the star Sirius. It did not use the sun or moon in determination of the calendar and did not closely fit the requirements of Scripture. The Egyptians concurrently used a second lunar calendar based on beginning the month on the morning following the last observation of the old crescent moon.

A basic calendar feature may be directly derived from the creation account, and that is the week of seven days. Attempts to establish the week from sources outside Israel have met with little success.10 The week has remained independent of the month and lunar cycles. However, the early Sumerians held festivals for the moon on the first, the seventh and the fifteenth days of the month.11 The seven-day cycle ending with the Sabbath later appears extended to a week of years as the Sabbatical year and a week of Sabbatical years as a Jubilee.

Before the Exodus the only specific Biblical reference to dating was at the time of the Flood. From month and day II 17 to VII 17 there were 150 days, which is the number of days the ark was afloat (Gen. 7:11, 8:3-4). Several calendars have been suggested to fit this pattern, and these are laid out by the month in Chart I. All months are shown as thirty days, except thirty-one for the end of the quarter months of the Jubilee calendar and twenty-nine days probable for months I, IV and VII of a lunar calendar. Jewish inclusive reckoning is used, as will be discussed below.

The Flood calendar is sometimes used to support the proposed existence of a "prophetic" year. This is reported related to an early Chaldean calendar of twelve months of thirty days, or a 360-day year.12 However, with normal inclusive reckoning there would be 151 days, not 150. It would be necessary not to count the first or last day to reduce the count to 150. A 360 day year seems too crude for any peoples aware of yearly cycles. This supposed calendar was not based on the observation of the sun, moon, or any known star, a requirement of the Creation calendar. The thirty-day months imply an artificial calendar such as that used in Egypt, with its 365-day year.13 Thus, an artificial calendar of thirty-day months at the time of the Flood is unlikely, especially one of 360 days.

As will be discussed in the next chapter, there is also the claim that the calendar of the Pentateuch was the same as that described in Jubilees.14 This was a 364 day calendar of thirty-day months with an extra day at the end of the third, sixth, ninth and twelfth months.14A Such would have required 153 days for the ark to be afloat, too many days for the 150 days required by Scripture.

The calendar at the time of the Flood was most likely lunar. If II 17 and VII 17 are both counted by the usual Jewish inclusive reckoning, and months I, IV, and VII were twenty-nine-day months, then there were the correct 150 days when the ark was afloat. The months would have been 29, 30, 30, 29, 30, 30, and 29 days long, which is a not untypical sequence of lunar months based on observation. The synodic month, the interval between two conjunctions, averages 29.53 days long, but may vary by almost thirteen hours. The eccentricity of the orbits of the earth and moon cause the month to range in length from 29.26 to 29.80 days. Three successive thirty-day months were somewhat common, occurring about once in ten years, and known to the Babylonians.15 Even four successive thirty-day months, or rarely five, are possible.16 This possibility always existed, but the sages later limited that the year must contain at least four but no more that eight months of thirty days (BT, `Arakin 8b). Even if the first or last day was not counted, as some might insist, the calendar still could have been lunar. Also, there could have been 150 days from II 17 to VII 17 with a common sequence of lunar months if there was an observational error, particularly by beginning month II a day early or VII a day late. An observational error was a real possibility during the periods of extended overcast that must have preceded or accompanied the Flood. Since there is no artificial calendar that does not contain at least one day too many, according to inclusive Jewish reckoning, the Flood calendar was lunar.

The rains began on II 17 (Gen. 7:11) and the earth was dry in the following year on II 27 (Gen. 8:14). This could represent a lunar year of about 354 days plus ten or eleven days to complete a solar year. Such was the rabbinical explanation by the Middle Ages.17 This would confirm the luni-solar nature of the Flood calendar.

The Flood began in month II, but month I is not given as beginning in the spring or fall. All other numbered months in Scripture later refer to month I being Abib, or Nisan, and, by analogy, we might expect such here. Rain falling in the second month of the spring at the time of the harvests was a sign of God's displeasure (1 Sam. 12:17-18).18 A fall new year19 may seem necessary so that the Flood would coincide with the usual rainy season. However, such a requirement is not necessary for rains that were under Divine control. A fall new year would then place the end of the Flood when the land dried up in the same rainy month when it would start. Beginning the Flood in the fall presents no better logical solution. The numbering of months was likely from a spring new year.

The day may have been measured sunrise to sunrise. This seems suggested in a reference after the Flood, when Lot escaped from Sodom (twentieth century BCE?). His daughters got him drunk and had intercourse with him to preserve the family, "and it came about on the morrow, and the first-born said to the younger, `Behold, I lay last night with my father.'" (Gen. 19:34) The "morrow," also translated "next day," follows "last night" when the day begins at sunrise.

In summary, the calendar system at the time of the Flood was likely lunar. It is unlikely to have been an artificial calendar of 360 days, or 365 days as in Egypt, or the 364-day calendar of Jubilees. These all required more than the stated 150 days. Although not given in Scripture the months are likely, by analogy, to have been numbered from the spring. Rain at the time of the harvests in a spring second month would be an appropriate time for God to show His displeasure. A later passage suggests the day was measured from sunrise. This calendar seems like the one given by God to Moses at the time of the Exodus.

God gave the first explicit "Hebrew" calendar at the time of the Exodus from Egypt, and that system is here called the Exodus calendar. For the first time the Hebrews, as a nation, were independent. They were given laws and religious observances that required a consistent calendar system. Again, there is only Scripture to decide when the day and year began. The beginning of the calendar day and year is often confused with the rest periods, the Sabbath day and the Sabbatical year.

Two weeks before the Exodus God said to Moses, "This month shall be the beginning of months for you; it is to be the first month of the year to you." (Exod. 12:2) Scripture notes the timing of this month five days earlier, after the plague of hail, which states, "now the flax and the barley were ruined, for the barley was in the ear and the flax was in bud. But the wheat and spelt were not ruined, for they ripen late." (Exod. 9:31-32) This first month was Abib (Exod. 13:4, 23:15, 34:18; Deut. 16:1), which means "fresh ear" of grain and refers to the time when barley shoots into ear. This can be expected in Egypt to occur in March, a little before or after the Vernal Equinox. Thus, in the year of the Exodus Abib, later called Nisan, began in the spring.

Was Abib a lunar month or an artificial month, such as the thirty day months of the Egyptian calendar? The Hebrew "month" is also translated "new moon." The months of the Exodus calendar can be traced as lunar, as "on the first days of your months, you shall blow the trumpets over your burnt offerings." (Num. 10:10, 28:11) The first day of the month was tied to trumpets and burnt offerings and was later sanctified as the day of the new moon. During David's days this was suggested by such as, "blow the trumpet at the new moon," and "offer all burnt offerings to the Lord, on the Sabbaths, the new moons. . . ." (Ps. 81:3; 1 Chron. 23:31) The lunar observance of months was still noted shortly after the Babylonian captivity, as, "there was a continual burnt offering, also for the new moons." (Ezra 3:5) New moon festivals were prominent during the inter-testament period (Judith 8:6; 1 Macc. 10:34). Again, in the first century CE we find, "let no one act as your judge in regard to food or drink or in respect to a festival or a new moon or a Sabbath day." (Col. 2:16) The Jews and early Christians were still watching for the first appearance of the moon.21 There is no hint that there were two separate types of Exodus calendars in operation, as with the Egyptian 365 day astral calendar and their lunar calendar.22 Abib was a spring lunar month, the first month of a lunar calendar.

One passage is often used to try to establish that the year began in the fall month of Ethanim, later called Tishri, noting, "the Feast of the Ingathering (Tabernacles) at the end of the year." (Exod. 23:16) This does not establish an Ethanim new year, since the "end of the year" also can be translated "during the year."23 The LXX renders this as, "in the middle of the year," or, "within the year." In context, the Feast of Ingathering is the third of the three required feasts during the year and would be the last festival of the year specified by God, at the end of the festival year. Or, it may refer to the end of the harvest season, the end of the agricultural cycle. Such would be the interpretation of "at the turn of the year" (Exod. 34:22) as referring to the change from longer days to shorter days at the fall equinox. The observance of the Feast of Ingathering was two weeks into the month of Ethanim, and the calendar year did not end during the middle of that month.24 This single passage cannot establish a fall new year.

Since the trumpets and burnt offerings were associated with a "new" moon festival, the month must have begun with the new moon. This would likely have been with the first observation of the new crescent, a day or two after the invisible true new moon.

The known months of the Exodus calendar are: Abib, Zif, Tsach,25 IV, V, VI, Ethanim, Bul, IX, X, XI and XII. The numbered months in Scripture always refer to the year beginning with the spring month of Abib, and later Nisan. The months would have been twenty-nine or thirty days in length, probably in no set pattern, but based on observation.

Since twelve lunar months fall approximately eleven days short of a solar year some method of adjustment must be used to maintain the beginning of the new year at about the Vernal Equinox. This requires periodically adding, or intercalating, an extra or thirteenth month. The actual system by which this was done is not certain, but since the cutting of the barley sheaf must occur a few days after the Passover (Lev. 23:10-11), the extra month was probably added when the barley had not yet come into ear. If the ripening of the barley decided the new year, then a thirteenth month could only follow the twelfth month when the barley had not come into ear. Also, the addition of an intercalary month between the first and seventh months was not likely, because this would have upset the relationship of the required feasts in the spring and fall. The Exodus calendar was a lunar calendar periodically adjusted to the solar year by the addition of an extra month.

A 360-day calendar or the Jubilee calendar would have only twelve months with no intercalary month added to adjust to the solar year. Those who support such reckoning note, "Solomon had twelve deputies over all Israel, who provided for the king and his household; each man had to provide for a month in the year." (1 Kings 4:7) However, just as Scripture does not specify a thirteenth month, such was later in use. It is not specified who provisioned Solomon during a thirteenth month. Such a single passage cannot be conclusive for limiting the year to only twelve months.

Measurement of the day of the Exodus calendar was sunrise to sunrise. For example, the Passover commemorates the slaying of the first-born of Egypt, when God passed over the first-born of the sons of Israel. The Passover meal was eaten during the evening of Abib 14 (Num. 9:3), before the event it commemorates, which was, "at midnight that the Lord struck all the first-born in the land of Egypt." (Exod. 12:29) The night proceeding the Exodus was Abib 14. The Exodus occurred the immediate following morning when, "they journeyed from Rameses in the first month, on the fifteenth day; on the day after the Passover the sons of Israel started out boldly in the sight of all the Egyptians." (Num. 33:3) The daylight hours of Abib 15 immediately followed the dark hours and the midnight "Passover" of Abib 14. The day began at sunrise.

Further, the Day of Atonement begins in the morning, "on exactly the tenth day of the seventh month." (Lev. 23:27) Associated with this calendar day is a "Sabbath of complete rest to you. . . . on the ninth of the month at evening, from evening until evening you shall keep your Sabbath." (Lev. 23:32) Here the rest period begins the prior evening of the ninth day and ends at evening on the tenth day. During the Sabbath rest the day must change from the ninth to the tenth day, that time being at sunrise. The entire rest period is named by the second half of the rest period, the Day of Atonement. The specification that the rest period was "evening until evening" would not be necessary if it coincided with the calendar day. If measurement of the calendar day had been evening to evening, then it was only necessary to specify the calendar day, such as the Day of Atonement, Ethanim 10. The Sabbath rest beginning on the ninth should not be confused with the calendar day beginning the following morning of the tenth, the Day of Atonement.

In the preceding there is a Sabbath rest period not associated with the seventh day of the week. Similarly, the first and eighth days of the following Feast of Tabernacles are automatically Sabbath rests, whatever the day on which they fall (Lev. 23:39). A discussion of this subject in detail is found in the chapter, "The Preparation for the Sabbath."

The Sabbath did not coincide with a calendar day, but consisted of half of two succeeding days. Such was similar for the Sabbatical year, which began in the second half of one year, and ended in the middle of the following year. Confusion on this point by the early Jews eventually led to the "agricultural" calendar and the later Diaspora calendar, which began the year in the fall and the day at sunset. Such a calendar does not appear in Scripture.

The beginning of the day at sunrise is also found during the period of the Judges. Gideon laid out his fleece and "arose early the next morning." (Jud. 6:38) Here the night belongs to the preceding day. The day began at sunrise for the Levite who was told, "spend the night here that your heart may be merry. Then tomorrow you may arise early for your journey." (Jud. 19:9) When Israel mourned the tribe of Benjamin "it came about the next day the people arose early and built an altar." (Jud. 21:4) The next day began at sunrise.

During the time of Saul he intended to put David to death in the morning, but David was warned, "save your life tonight, tomorrow you will be put to death." (1 Sam. 19:11) Later it was Saul who died at the battle of Mount Gilboa the day after he visited the witch of Endor, when the ghost of Samuel said, "tomorrow you and your sons will be with me." (1 Sam. 28:19) Saul's last tomorrow was the following day, and the day began at sunrise.

In summary, the Exodus calendar was a lunar calendar with the months beginning with the sunrise following the first observation of the new crescent moon. The first month of the year was Abib in the spring which was probably determined by the ripening of the barley, at least during the early period. The beginning of Abib could occur a little before or after the Vernal Equinox. An extra twelfth month was added periodically to maintain Abib in the spring. The day began at sunrise. This is the calendar of Scripture up to the Babylonian captivity.

During the time of David a spring new year was still in use. When David sent Joab and his men against the Ammonites it was "after the year was expired, when kings go forth to battle." (2 Sam. 11:1, AV) This was after the winter, and the year was ended, in the spring.

The Exodus calendar with the spring new year was still in use when Solomon built his Temple. In about 968 BCE, "in the four hundred and eightieth year after the sons of Israel came out of the land of Egypt, in the fourth year of Solomon's reign over Israel, in the month of Ziv which is the second month, that he began to build the house of the Lord . . . And in the eleventh year, in the month of Bul, which is the eighth month, the house was finished . . . So he was seven years in building it." (1 Kings 6:1, 38) Here the numbered months are from Abib, or Nisan, which identifies that month as the new year. The Mishna says that "the first of Nisan (Abib) is the new year for kings." (Mishna, Rosh Hashanah 1:1) In the gemara, or commentary, rabbi Johanan said, "Here Solomon's reign is put side by side with the exodus from Egypt, [to indicate that] just as [the years from] the exodus from Egypt are reckoned from Nisan (Abib), so [the years of] Solomon's reign commenced with Nisan (Abib)." (Rosh Hashanah 2B) The seven years refer to the time to build the Temple, and not to regnal years, but also only make sense when referring to an Abib new year.26 Solomon's reign and the calendar year were from Abib to Abib.

In 931/930 BCE, Solomon's kingdom became divided, and the northern Kingdom of Israel under Jeroboam separated from the southern Kingdom of Judah under Solomon's son, Rehoboam. The two kingdoms must have reckoned the reign of their kings by a different method. Rehoboam and Jeroboam began to rule about the same time, and Ahaziah (Judah) and Ahaziah (Israel) were killed at the same time by Jehu, in about 841 BCE. For Judah there were five rulers during this period, and the reigns given in Scripture total seventy-nine years. There were seven rulers of Israel during the same period, and their official reigns totaled eighty-six years. The difference was because Judah used accession reckoning, which did not count the first year of a ruler. The first partial year was allocated to the preceding king, and the years can be directly added. Israel used non-accession reckoning where the first partial year was counted as year one, and one year must be subtracted from each king's reign before adding. That is, the eighty-six years of the kings of Israel minus seven years for the seven kings equals the seventy-nine years of the kings of Judah. Judah used accession reckoning, and Israel used non-accession reckoning.27

Judah and Israel also appear to have reckoned the new year for kings from a different month. Rehoboam would have continued using the Exodus calendar and accession reckoning as had his father, Solomon.28 Jeroboam, perhaps initially as a political move, appears to have adopted an agricultural calendar that began in the fall for civil purposes. It is possible that Solomon died and Rehoboam became king in the second half of the year beginning in Abib of 931 BCE. Jeroboam may have been proclaimed king of Israel after the Abib new year in 930 BCE, in the year following Rehoboam. By adopting a calendar from the fall he backdated his reign to the prior Ethanim, into the same half of the year when Rehoboam became king. Also, by changing to non-accession reckoning Jeroboam's official regnal year one preceded Rehoboam's by six months.

Jeroboam also had a religious reason to change the new year. He feared that his people would go to the festivals in Jerusalem, return to Rehoboam, and kill him. So Jeroboam forbade going to these festivals (1 Kings 12:26-33). He set up golden calves for worship and instituted a new festival. Since the calendar beginning in Abib was tied to the festivals in Jerusalem, he may have changed to a fall new year to upset the religious calendar.29 It can be inferred that Jeroboam's civil, and perhaps religious, year began with Ethanim (Tishri), although this is never confirmed in Scripture. This agricultural calendar was used to measure the reigns of the kings of the northern Kingdom of Israel until its end in 722 BCE. A year beginning in Ethanim was likely used for civil purposes in the north.

A fall calendar new year in Scripture does not occur, unless a calendar year is confounded with the rest period of a Sabbatical year. The basis of a fall calendar is the agricultural cycle and its sequence of planting/harvesting. The Sabbatical year was observed in the same sequence, no planting/no harvesting, and the rest began from the fall month of Ethanim. This agricultural cycle does appear as a calendar, of sorts, on the "Gezer Calendar."30 This small limestone tablet from Tell Gezer in Judah dates to about 925 BCE. It reads:

His two months are (olive) harvest
    His two months are planting (grain)
        His two months are late planting
His month is hoeing up the flax
    His month is harvest of barley
        His month is harvest and feasting
His two months are vine-tending
    His month is summer fruit

The first month of this calendar can be assigned to Ethanim, or Tishri. This was most likely the calendar of the Kingdom of Israel. There is no evidence to support the reckoning of the day from sunset, although development of a sunset observance for the Sabbath would be expected.

Back in the Kingdom of Judah the new year was still reckoned from Abib. The sole reign of Hezekiah began in about 715 BCE, and, "in the first year of his reign, in the first month" (2 Chron. 29:3) he began religious reforms. Because the priests had not been consecrated in sufficient numbers, he "decided to celebrate the Passover in the second month." (2 Chron. 30:2) Thus, the first month must refer to Abib.

During the later decades of the eighth century BCE, the Assyrians took the Kingdom of Israel into captivity, which ended with the destruction of Samaria in 722 BCE. This dispersion of the Hebrews, followed later by the many exiles from the sixth-century Babylonian captivity, became known as the Diaspora, or scattering. The first captives would have taken with them their agricultural calendar beginning in the fall. They became dispersed among nations from Babylon to Greece that reckoned their day from sunset, and that also became fixed in the Diaspora calendar.

The calendar of the Diaspora evolved into the present Jewish calendar. The Pharisees later adopted this method of reckoning. It became their standard passed on through the Mishna and later Talmud, to the exclusion of the Exodus calendar. The present calendar was also finalized in the Diaspora, apart from the Temple ritual of Jerusalem. Jeroboam would be pleased at the success of his calendar split.

The Neo-Babylonian Empire began under Naboplassar in 626 BCE. By the end of the seventh century he had subdued the Assyrians and most of the territories of the early Hebrew Diaspora. His son, Nebuchadnezzar, continued the campaigns against the Egyptians and Judeans.

These Babylonians had the most accurate calendar of the period. The Persians continued to use this calendar until toward the end of the first century CE. Both the Babylonian and Persian kings, as with the Judeans, used accession reckoning from a spring new year.

The Babylonian calendar was a luni-solar calendar that began the new year according to the Vernal Equinox in the spring.31 The first month was Nisanu, which began with the new moon after the Vernal Equinox. The months began with the evening following the first observation of the new crescent moon.

The months of the Babylonian calendar were Nisanu, Aiaru, Simanu, Duzu, Abu, Ululu, Tashritu, Arahsamnu, Kislimu, Tebetu, Shabatu and Addaru. The intercalary months were standardized from the early fourth century to include seven in a nineteen year cycle. These included six second Addarus after the twelfth month in years 3, 6, 8, 11, 14 and 19 and one second Ululu after the sixth month in year 17 of the cycle.

A big difference between the Exodus calendar and Babylonian calendar was that the Jewish calendar could begin before the Vernal Equinox. However, the later Babylonian new year only began following the Vernal Equinox. However, the early Babylonian calendar did sometimes begin before the Vernal Equinox. For example, the new year fell as early as March 6 in 607 BCE and March 11 in 564 BCE, but not before March 24 from 499 BCE to 75 CE.32 Why the change? The Babylonians were keen on astrology, and their observations of the celestial bodies led to the most accurate of ancient calendars.33 The Babylonians developed the divisions of the celestial sphere into thirty-degree increments that divided the night sky into twelve sections. The main star constellation in each of these sectors is the basis of the names of the signs of the zodiac, and the first sign was Aries. Before the fifth century BCE the Babylonians may have used the position of the sun in Aries to determine their new year, as well as the Vernal Equinox. The Babylonians identified the shift of the constellations due to the precession of the equinoxes. In about 500 BCE the astronomer, Naburiannu, located the equinoxial point in ten degrees of Aries; in about 373 BCE Kidinnu located it at eight degrees.34 In the fifth century BCE the sun entered the sector of the constellation Aries on about March 14, shortly before the Vernal Equinox. Because of the precession of the equinoxes, by the first century CE the sun entered Aries close to the Vernal Equinox, about March 21. Today the sun appears behind Aries in the latter part of April, the position of the constellation having moved into the second sign, or sector. The adjustment of the Gregorian calendar did not correct this shift of the relative position of the stars of the zodiac. The Babylonians had noted that the sun entered Aries progressively closer to the Vernal Equinox and would soon enter Aries only after the Vernal Equinox. As such, the new year for the Babylonian calendar locked on beginning after the Vernal Equinox, instead of when the sun entered Aries.

Abib could begin before the Vernal Equinox, but Nisanu, the first month of the Babylonian calendar, only began after the Vernal Equinox. This relationship can be tested.35 Also, a claimed scriptural error in dating the fall of Jerusalem can be resolved. Conversion dates from the Jewish months to the Julian calendar are calculated; poor weather or deficiencies in existing tables may shift the date by a day.36 There is no indication in Scripture that there was any change to the Exodus calendar between the Exodus and the Babylonian captivity. From the Babylonian record we know that Jerusalem fell to them the second time on the second of Addaru (the twelfth month), or March 16, 597 BCE. This was still the seventh year of Nebuchadnezzar according to Babylonian accession reckoning from Nisanu. Scripture relates that, "the king of Babylon took him [Jehoiachin] captive in the eighth year of his [Nebuchadnezzar's] reign." (2 Kings 12:42) This description occurred when, "at the turn of the year King Nebuchadnezzar sent and brought him to Babylon." (2 Chron. 36:10) The Biblical reference is to accession reckoning from Abib, but here says it is Nebuchadnezzar's eighth year, not his seventh. This is because according to the Exodus calendar the first day of Abib and the Jewish new year began on the morning of March 14. This was two days before the fall of Jerusalem and the beginning of the eighth year of Nebuchadnezzar according to Jewish reckoning. The Bible and the Babylonian record are both correct. The new year of the Exodus calendar began one month earlier than the Babylonian new year when the new moon was visible in the two weeks before the Vernal Equinox. When the new moon became visible in the two weeks after the Vernal Equinox the Exodus calendar and Babylonian calendar were approximately equal, allowing for the difference between the day beginning in the morning and in the evening.

[Correction: The Babylonian and Jewish Calendars both fell in the twelfth month in 597. The Babylonian's used non-inclusive reckoning where the partial first year of Nebuchadnezzar was counted as year 0, it still being reckoned as the 21st year of Nabopolassar. The Jews used inclusive reckoning where the first partial year was counted as year 1. The Babylonian 7th and the Biblical 8th are the same year.]

The Jews were now separated from Jerusalem and their Temple ritual. The influence of the Babylonian calendar was soon to be felt.

1. G. Moyer, "The Gregorian Calendar," SA 246 (1982).

2. H. W. Armstrong, The Plain Truth About Easter (Pasadena: Worldwide Church of God, 1973) equates the name "Easter" with the idolatrous "Queen of Heaven" and teaches a return to observing the Passover instead of Easter.

3. The regression is due primarily to two factors, the first being that the actual mean solar tropical year was a little less than the 365¼ days of the Julian calendar.  Second was the precession of the equinoxes, so that the Vernal Equinox regressed in relation to the sidereal year.

4. G. Ashby, "Reflection on the Language of Genesis 1 & 2," Sem 6(1978).

5. J. P. Lewis, "The Days of Creation: An Historical Survey of Interpretation," JETS 32 (1989).

6. T. Key, "How Long Were the Days of Genesis?," JASA (September 1984), 159-161 provides a brief summary of the basic interpretations and concludes that "Creative days were vast periods of time."

7. L. Lavallee, "Augustine on the Creation Days," JETS 32 (1989).

8. J. Barr, "Why the World was Created in 4004 B.C.: Archbishop Ussher and Biblical Chronology," JRUL 67, 2 (1985).

9. The Hebrew is "one day," not "first day," as found in some translations such as the NIV.

10. J. Lewey, "The Origin of the Week and the Oldest West Asiatic Calendar," HUCA 17 (1942-43) attempted to establish the origin of the week in Assyria, but this has not been borne out by subsequent research.

11. W. W. Hallo, "New Moon and Sabbaths: A Case-study in the Contrastive Approach," HUCA 48 (1977).

12. R. Anderson, The Coming Prince 10th ed. (Grand Rapids, MI: Kregel, rep. 1980) and M. F. Unger, Unger's Bible Dictionary (Chicago: Moody, rep. 1981).  Used by H. W. Hoehner, Chronological Aspects of the Life of Christ (Grand Rapids: Zondervan, 1977), 135-138 in an attempt at an exact solution to the Seventy Weeks in Daniel.

13. R. Gleadow, The Origin of the Zodiac (London: Cape, 1968), 212.

14. A. Jaubert, "Le Calendrier des Jubiles et les Jours Liturgiques de la Semaine," VT 7 (1957); S. Zeitlin, Studies in the Early History of Judaism (New York: KTAV, 1973), 183-193; J. C. Vanderkam, "The Origin, Character, and Early History of the 364-Day Calendar: A Reassessment of Jaubert's Hypotheses," CBQ 41 (1979).

14A. Newly deciphered Dead Sea Scroll confirms 364-Day Calendar used at Qumran. https://www.biblicalarchaeology.org/daily/news/qumran-community-364-day-calendar/  

15. S. Langdon & J. K. Fotheringham, The Venus Tablets of Ammizaduga (London: Oxford Univ. Press, 1928), 98; R. A. Parker, "The Beginning of the Lunar Month in Ancient Egypt," JNES 29 (1970).

16. A. E. Samuel, Greek and Roman Chronology (Munich: Oscar Beck, 1972), 15.

17. F. H. Cryer, "The Interrelationships of Gen 5,32; 11,10-11 and the Chronology of the Flood (Gen 6-9)," Bib 66, 2 (1985), 252.

18. Mishna, Ta'anith 1:7.

19. Josephus, Antiquities I 3:3, written about 93 CE, says the Flood was the second month from Tishri.

20. The generally accepted archaeological date for the Exodus is in the thirteenth century and the scriptural date in the fifteenth century.  For a reconciliation of these two positions in the sixteenth century see K. Doig, "The 1552 Exodus," C&AH 12, 2 (1990), 147-157.

21. T. Thorton, "Jewish New Moon Festivals, Galatians 4:3-11 and Colossians 2:16," JTS NS40 (1989).

22. A. Cooper and B. R. Goldstein, "The Festivals of Israel and Judah and the Literary History of the Pentateuch," JAOS 110, 1 (1990), 19-31 see the Biblical account as representing a conflation of different festival calendars.  A late redactor, RJE, is seen to have combined a festival tradition of Judah based on a solar year with lunar months reckoned from the sunrise following the last observance of the old moon, in the Egyptian style, and a Northern Kingdom lunar calendar based on the day beginning with first visibility of the new moon at sunset.  This approach may be acceptable if the Exodus is a myth and these calendars projected back to that time.  The two calendars supposedly in the Pentateuch could not exist until after the division of Solomon's kingdom, some half a millennia after the death of Moses.  The authors' approach fails from multilevel assumptions, which includes the presumption that Scripture was manipulated by the theological aims of later redactors, rather than by God.

23. M. L. Rodkinson, trans., Babylonian Talmud (Boston: New Talmud Publishing Society, 1916) 3:XIX.

24. J. B. Segal, "Intercalation and the Hebrew Calendar," VT 7 (1957), 276 translates as the "going forth of the year," and uses the ten-day epact beyond twelve lunar months to explain the Jubilee Year opening on Tishri 10.  J. Morgenstern, "The Three Calendars of Ancient Israel," HUCA 1 (1924), "Additional Notes on `The Three Calendars of Ancient Israel'," HUCA 3 (1926) and "Supplementary Studies in the Calendars of Ancient Israel," HUCA 10 (1935) claims that "calendar II" began the new year on II 10.  His "calendar I" was a solar calendar that used the Canaanite-Phoenician names of Abib, Ethanim, etc.  The numbered months represented his luni-solar "calendar II."  "Calendar III" was also luni-solar, but used the borrowed Babylonian month names, with the new year shifted back to the spring.

25. The word Tsach appears in Isa. 18:4 and would better be translated, "like the heat of the month of Tsach."  An ink inscription of a sixth-century clay jar from Arad identified Tsach as the third month.  The use of Tsach rather than a number or Sivan would imply that the Exodus Calendar was still in use shortly before the Babylonian captivity.

26. The conclusions of E. R. Thiele, The Mysterious Numbers of the Hebrew Kings (Grand Rapids, MI: Zondervan, 1983) are reversed in reckoning the kings of Judah according to a Tishri year and the kings of Israel according to a Nisan year. His diagram (p. 52) was to illustrate that Solomon reigned Tishri to Tishri. He assumes that the new year can be measured from Tishri, even though the months are measured from Nisan, for which there is no scriptural evidence. He also assumes that the seven years in building are to be compared to regnal years, rather than a basic length of time.  He compares Tishri years against a Nisan standard and incorrectly concludes there are seven years only from Tishri. The bottom comparison years on his diagram must be slid back six months to coincide with the Tishri marks, not the Nisan marks. Then there are correctly eight regnal years to build the Temple, inclusive years four to eleven, whether measured from Nisan or Tishri. According to his chart the actual time to build the Temple was six and a half years on a Tishri calendar and seven and a half years on a Nisan calendar, only the later better describing "seven years in building."

27. The kings of Judah used accession reckoning from Abib (Nisan) from David to Zedekiah, with the exception that Athaliah and Joash used non-accession reckoning from Abib during the disruption of the dynasty. The kings of Israel only used non-accession reckoning from Ethanim (Tishri) from Jeroboam until the end of the northern kingdom. The Scriptures of the entire period of the kings can be reconciled to themselves and history by the above reckoning. This discussion, however, is beyond the scope of the present work.

28. David used accession reckoning. King David was "in Hebron, and there he reigned seven years and six months.  And in Jerusalem he reigned thirty-three years." (1 Chron. 3:4) Here the total of his reign is forty and a half years.  Officially, "the days that David reigned over Israel were forty years."(1 Kings 2:11)  The extra half year was not part of his official reign, and can only be allocated to the last year of the reign of Saul.  Solomon and the following kings of Judah continued this accession reckoning.

29. J. Morgenstern, "The Chanukkah Festival and the Calendar of Ancient Israel," HUCA 21 (1948), 398-399 suggests that Jeroboam revived an agricultural religion based on a pentecontad calendar, which Solomon had abolished.

30. J. Finegan, Handbook of Biblical Chronology (Princeton: Princeton Univ. Press, 1964), 33. For the Hebrew and another translation see Morgenstern, "Additional Notes on the Three Calendars." HUCA 3, (1926), 86-87.

31. J. Finegan, Handbook of Biblical Chronology, 29-33; R. A. Parker & W. H. Dubberstein, Babylonian Chronology 626 B.C.-A.D. 75 (Providence: Brown Univ. Press, 1956).

32. Parker & Dubberstein, Babylonian Chronology, 27-28.

33. Gleadow, Zodiac, 154.

34. Gleadow, Zodiac, 74.

35. All Babylonian dates are taken from the tables of Parker and Dubberstein, Babylonian Chronology. These were calculated from Carl Schoch's tables in Langdon & Fotheringham, The Venus Tablets of Ammizaduga, and attested by extensive Babylonian documents. The author here used Schoch's tables to calculate new moon visibility and the beginning of lunar months in other locations such as Jerusalem or points in Egypt. These tables give Julian dates.

36. L. W. Casperson, "The Lunar Dates of Thutmose III," JNES 45 (1986) notes several small errors in the assumptions in the tables of Carl Schoch and those of Neugebauer, and with computer-generated new moon calculations shows previously calculated dates to sometimes cause an error by one day if time of visibility is near the time of day change.