Mathematical Bias and the Biblical Calendar
(Revised 2021)

By: Shawn Richardson

Section 5:


Now that we have established the Biblical Day and Month, one major element remains: the Biblical Year. Just as our mathematical bias persuaded us to assign a fixed number of days to a given month, we are also determined to assign a fixed number of months in a given year. For those of us comfortable with the Gregorian calendar, we assign twelve months per year. As we learned in the previous chapter, a lunar cycle lasts just over 29 1/2 days and does not easily divide into the solar year. The solar year lasts just a few days shy of 12 1/2 lunar months. But, does the Bible explain to us how many months we should keep in a given year or when the New Year should begin? To understand the answer to this question, we need to turn to the scriptures. We are told directly by Yehovah Himself in Exodus 12:2[1]:

This instruction was given to Israel at the time of their exodus out of Egypt. The following statements continue the rules of keeping the Passover. We also know that the Passover was observed in the same month, the first month (or renewed moon). Exodus 13:3-4[1] further explains the month Israel left Egypt:

Or this can be translated as the "month of the aviv." Understanding the definition behind the word month as being translated from chodesh (Strong's 2320), we can understand these verses as saying:

So, to understand when the Biblical Year begins, we just need to know one thing: when is the renewed moon of the aviv? Aviv (also translated abib) is used here as a very specific term. We will see that this Hebrew term is not necessarily a proper name given to the first month; rather it is a descriptive state of being.

Aviv Barley

Proper names within the Hebrew language, though, always contain an inherent meaning (and still do today) within their construct. Unlike our traditions in the Western World where names are merely a unique reference label (not much unlike a number assigned by a computer), the Hebrew language is broken down into representative segments (similar to a group of picture images that, when combined, form a word or name). When Yehovah gives a name for someone or something, the meaning is always perfectly represented. As we saw with the King James, some translations phrase this as "the month Aviv", as using a proper name. Others say "the month of the aviv". Either way, we must look at the meaning behind the term or name aviv. Let's start with the King James' version from the Strong's Concordance (Strong's 24), which translates as[3]:

Exodus 13:4 specified that the first month was of aviv. With this definition, we would infer that the new moon crescent was of green, young ears of grain in the fields. Another translation is often green, tender ears. In either case, we see that the name Aviv itself is a reference to the growing stage of crops. This definition, however, is derived outside of Biblical resources (as there is no "root" word used within the Bible to better define its meaning). So, we must look further for other references in order to understand the context. Exodus 23:15[1] refers, once again, to the month of Aviv:

Additional references to Aviv are found in Exodus 34:18 and Deuteronomy 16:1. As we mentioned earlier, seasons (as we refer to them today) were only defined as summer and winter in the Bible. Essentially, the year was broken into two parts - the season of harvesting and the season of winter. People were agrarian in nature and were quite aware of which crops would be ripened and when. The people at the time of Moses would have identified perfectly with Yehovah's description of the first month. They would have understood what aviv referred to and as being related to crops. We are also given a very specific description during the plague of the hail prior to Israel leaving Egypt in Exodus 9:31-32[1]:

This describes a state of mature barley as being brittle enough to be damaged by hail and not flexible (Afilot) enough to take on the barrage of the storm. Barley is the first cereal grain to be harvested every year as it grows during the winter. This description, though, makes the translation "green ears of corn" a bit misleading. The Karaite Korner, the group dedicated to barley searches within the land of Israel, claims the Strong's definition of green ears is not completely accurate. They explain in their FAQ page that[61]:

The full meaning of this passage and its ramifications for understanding the agricultural term Aviv is discussed in an article titled "Abib (Barley)"[62]. With the additional support from Exodus 9 above, we can conclude that Aviv is a reference to the state of the harvest - more specifically, that of the barley harvest.

Wave Sheaf

The use of barley crops in an aviv state to determine the year is further supported after Israel arrived in the Promised Land where we are told that, during the Feast of Unleavened Bread, Yehovah commanded a wave sheaf offering (Leviticus 23:10-11)[1]:

A sheaf of ripened barley, similar to what would have been waved at the temple during the Days of Unleavened Bread

This offering was brought from the first cut barley of the harvest and was the first of the grain to be presented for consumption as He also commanded that none of the new harvest could even be consumed until this event took place in verse 14[1]:

Since it was commanded that unleavened bread be eaten at the time of Passover and during the festival, this scripture was stating that no bread should be made or grain parched from the new crops until this ceremony had taken place. This wave sheaf offering began the Feast of Firstfruits - or the count to Pentecost. Obviously, the requirement of having ripened barley available for the wave sheaf offering was necessary to start the year and, since the people could not eat it until it was offered, it was vital to identify the correct month that would be of Aviv. As the article above references, Leviticus tells us, in even further detail, what conditions (or stages of growth) the barley would be acceptable as an offering - giving us a further description, at minimal, to the meaning of Aviv. Leviticus 2:14[1] states:

This specifies that the firstfruit offering of barley could be either 1) parched in fire, or 2) as crushed Carmel. Therefore, at the time the grain is given as an offering, if the seed within the barley heads have not matured past the milky stage and would simply burst open when squeezed or parched in a fire, it is not yet aviv. However, if it is simply moist, but not quite enough to be crushed into flour, a fire could be used to remove the moisture and, then, be crushed. At this stage of growth, Barley can still be visually green in color, but will have tell-tale signs of yellowing. It's at this stage that the barley would be acceptable for the offering.

If a renewed moon arrived with no aviv barley ready to harvest, then declaration of a new year would not begin until the following renewed moon sighting. This would mean that the barley harvest could mature to a level of hardened grain - visibly yellow in color. For more information regarding the barley harvesting, see Growth and Development Guide for Spring Barley[15].

There are those that argue if any kind of green herbage exists in the land then the month should be considered Aviv. But as we have seen, it is required that the plant be matured enough to be parched in fire, at a minimum. Then the question becomes: does the year begin when any barley plant is discovered at the necessary level of ripeness in a particular location or do you wait until it can be found throughout all the land? Obviously, waiting for the entire region to be filled with aviv barley would be like waiting until the moon was full to determine it was renewed. However, identifying how much aviv barley is enough has often been a topic of contention.

Naturally, a field of barley (especially wild barley) will often vary in ripeness from one stalk to another. As a field ripens, it is very common to find a mixture of barley stalks in varying stages of ripeness - especially on the outside borders near roads or rocky areas that absorb higher amounts of heat than the rest of the field. This can cause "pockets" of barley to be more mature than the majority of the remaining field. It is debatable on how much barley needs to be aviv to properly determine the new year.

There are some that believe any amount of barley found eligible and in enough quantity (a bundle) for the wave sheaf offering should be considered aviv. This view is often coupled with an urgency to find aviv as early as possible with the understanding that Deuteronomy 16:9 is a commandment that no one was allowed to cut or harvest any new barley until the wave sheaf was offered[1]:

This, of course, is describing the count to Pentecost that begins during the Days of Unleavened Bread when the wave sheaf is presented. The instruction for counting is repeated in Leviticus 23:15[1]:

The verbiage "put the sickle to the grain" is paraphrasing the wave sheaf offering that was presented by the priest, not a commandment for everyone to refrain from harvesting. If everyone was restricted from using a sickle until after the wave sheaf was presented, it would be impossible since - at minimum - the priest would have to use his own sickle in order to prepare the wave sheaf offering itself. Not to mention that no one would be able to present their own first-fruit offering as none would have brought any with them to be made available to eat while at the Feast - they would have to wait until they got home, and then hope their fields weren't too far gone because they waited too long.

The Jewish Encyclopedia describes the wave sheaf ceremony conducted at the temple[65]:

This ceremony was, essentially, a national ceremony to kick-off of the harvest season. Although individual farmers could still bring their own first-fruit offering and would have likely brought their own barley to eat at the festival, it's clear that the barley needed to be mature enough that most farmers were aware the fields were becoming ripe. The most important factor, though, was that barley would be ready in time to perform this ceremony. Given that farmers at the Feast of Unleavened Bread would have had barley in a variety of matured levels on hand would be the reason why the first-fruit offering was flexible to allow for parched or mature barley.

Although the entire barley harvest lasts anywhere from six to eight weeks, it's important for everyone to understand that once barley does become fully mature, the window of time to harvest it is very short - otherwise it becomes brittle and falls apart, disintegrating in the fields. If they were forced to wait several weeks for the wave sheaf ceremony to be performed, remain at the Feast for up to seven days, and then travel back home this would actually make traveling to the Feast impractical for most farmers - hence many people's urgency to want to declare aviv as early as possible. But this restriction did not exist, the only requirement was that they not eat of the new grain until the offering was made.

Common sense would then imply that enough aviv barley should exist in a field that any farmer would be willing to take the effort to begin harvesting his field. Small, insignificant pockets or edges would not be worth the trouble for a farmer to consider harvesting. It would be at this point that most farmers, preparing to harvest their fields, would clearly know that the next renewed moon would be the first of the year. By the time Passover arrived, not only would the high priest have barley nearby available to harvest for the Wave Sheaf given at the temple, but individual farmers should also have their own first fruit offerings of new barley (whether fully matured or parched in fire) to take with them to the Feast of Unleavened Bread (in Jerusalem) and begin to eat of that year's new crop while there.

Scripture, obviously, does not spell out clear instructions to make either side of this argument clear. This leads to various interpretations and differences of opinion. There are several groups and organizations that do conduct aviv searches every year that usually do provide enough data for one to make a final decision.

Although barley may be located in various locations throughout the world, it hasn't always been the case. Obviously referring to barley grown in controlled conditions under man's guidance should not be considered when looking for aviv barley at the time of the renewed moon. This, then, would lead us to question the authenticity of barley exported to various locations around the world that take advantage of climate conditions at various times throughout the year. This means that our best, most logical choice would be to look to indigenous barley - the geographical origin where barley historically grew naturally.

Natural, or wild, barley is referred to as Hordeum spontaneum. Its origins spread from regions of North Africa and Crete in the west (primarily Egypt), to Tibet in the east. It grows most abundantly in the Fertile Crescent region (with modern-day Israel located in the middle of this region)[63]. According to the scriptures, the original borders of the Promised Land extended well beyond the modern-day borders of Israel. Yehovah's borders included all of the land from the river of the Nile in the east (in Egypt) to the Euphrates River in the west (located in modern-day Iraq). This entire region is located directly inside the Fertile Crescent. The earliest evidence of wild barley in an archaeological context comes from the Epipaleolithic at Ohalo II at the southern end of the Sea of Galilee. In other words, barley originated in Israel with the Fertile Crescent having the conditions in which it grows naturally and is relatively drought tolerant[64]. Therefore, this geographical region would provide a point of reference that would match that within scripture. This area would have included Egypt, which is where the people of Israel were located when they were instructed to use the aviv to begin their Biblical Year. Although the Fertile Crescent region contains both harvested (Hordeum Vulgare) and wild (Hordeum Spontaneum) barley, the wild barley is much rarer the further you go outside of this region[57].

Just as with the renewed moons, there are some that believe you must only observe barley from Jerusalem; however, the city itself does not have a history of growing barley - either cultivated or wild. Barley is generally located a few miles outside of Jerusalem itself, closer to the river.

We can see, then, that scripture gives us yet another sign on which to measure our Biblical Calendar. The renewed moon, however, remains the primary marker within the timepiece for the start of the Biblical Month with the added caveat of aviv barley, being ready to harvest, telling us that renewed moon is the first to begin counting as a new Biblical Year. The Israelites would have clearly understood the significance behind the word/name Aviv. Today, many often dismiss this term as simply an arbitrary name once assigned to a now defunct calendar no longer in use. Not even the modern Hebrew calendar retains this phrase, which uses Nissan as the name of the first month, giving no correlation to barley whatsoever. But now that we see the context within scripture, we can see Exodus 34:18[1] as commanding Yehovah's people to do the following:

Historical Evidence

Now that we have read the instructions regarding the Biblical Year, we may notice that there is no scriptural foundation for a pre-determined number of Biblical Months within a given year. Just as a lunar month lasts 29.53 days, a solar year (a full orbit of the Earth around the Sun) lasts 365.24 days (or about 12.37 lunar months). Yes, this means that a Biblical Year can last either 12 or 13 months. The calculated Hebrew calendar resolves this by inserting a 13th month (or leap-month) into the year at various times on a rotating 19-year cycle. This is referred to as intercalating a month, or to add a month. This is similar to the Gregorian calendar inserting a leap-day once on a 4-year cycle (unless the year is divisible by 100 but not 1000). Of course, there are those that believe the Hebrew calendar always existed. But this is not true. The Wikipedia Encyclopedia[20] confirms:

As we saw with the renewed moon the Orthodox Rabbi, Arthur Spier, described the thin waxing crescent as being the start of the Biblical Month historically. Spier also explains that, "the Talmudic sources report that the Council," referring here to the Sod Haibbur Calendar Council, "intercalated a year," or added an extra month to the year, "when the barley in the fields had not yet ripened," amongst other things[44]. The Karaite Jews, who currently practice observation of the waxing crescent, also conduct aviv barley searches every year to determine if the upcoming twelfth renewed moon will coincide with any indigenous fields found in the Holy Land.

Through the simple, consistent task of observing barley within fields, we can rather easily determine that the new year is ready to begin (especially if it is communicated at the time of the renewed moon). It is another visible sign given to us directly by Yehovah Himself when he called the first moon Aviv - regardless if there has been 12 or 13 months since the last harvest.

The use of crops by the Children of Israel has always been intricately tied directly into the Festivals of Yehovah that were kept within their seasons. The Wikipedia confirms this connection[46]:

Judaism 101 further makes this connection to the ancient calendar explaining when the 13th leap-month would be inserted prior to the first month[35]:

We see here that Israel (the Sanhedrin) considered several variables, over time, when the renewed moon was declared the first renewed moon of the year. But only the term Aviv is directly instructed by Yehovah within scripture. Only with the method of observation can all of the signs given by Yehovah in scripture be preserved: the sun, moon and harvest season.

So now, just as we learned that the new moon crescent arrives with the blowing of a trumpet while gathering together in fellowship, we see here that the new moon crescent of Aviv arrives at the same time, but with the existence of ripened barley (capable of being harvested) in the fields within the Promised Land. Communication of such findings would have been simple as everyone came together during the New Moon Festival. If there were no reports of aviv barley in the fields, then another month was added to the current year.

Biblical 13th Month

One question I hear often is where in the Bible do you ever find reference to a thirteenth month? To answer that question, let's return for a moment to the topic of the flood and the account of Noah referencing particular days of the year. Is it possible that Noah kept a method of observation with the celestial movements being similar (or the same) as we see them today? We already mentioned that the scriptures tell us that the rain began to fall on the 17th day of the 2nd month in Genesis 7:11. Verse 12 describes the rain lasting 40 days and 40 nights followed by an additional period of 150 days in verse 24 where we are told the waters prevailed (remained). The next chapter repeats another 150-day period in verse 3 that describes the period of time the waters abated (decreased). Some question whether this describes two periods of 150 days or just one. However, it would not be logical that the waters could prevail (remain) and abate (decrease) at the same time nor does it fit in the overall timeline, as we will see. Those that believe Biblical months were once measured as a fixed number of 30 days each assume the flood consisted of two 150-day periods starting on the 17th day of the Second month and ending on the 17th day of the Twelfth month. Additionally, it is assumed that the initial 40 days were part of the first 150-day period. This theory seems to be supported in Genesis 8:4 that describes the ark coming to rest on the 17th day of the Seventh month upon the Ararat mountains (what seems to be exactly five 30-day months, or 150 days, since the rain began to fall - assuming, of course, the ark came to rest on mount Ararat on the exact same day the waters began to abate).

The story of Noah continues, however, where we are told that the flood waters were no longer seen on the first day of the year in Genesis 8:13 (with the ground still likely to be saturated and not completely dried to walk upon until the 17th day of the Second month as described in Genesis 8:14). So, what happened between the supposed 17th day of the Twelfth month and the first day of the following year?

Now that we know an observed calendar year can last either 12 or 13 lunar months, let's consider the total number of days that seem to be described in the story of Noah. First, the rain began to fall either 45 or 46 days from the start of the year (the first month being either 29 or 30 days, plus 16 days in the second month). If you add 40 days/nights for rain, 150 days for water to prevail (remain) and 150 days for water to abate (decrease), you end up with 385 or 386 total days in the first year. This just happens to fit the total number of whole days it takes for 13 Synodic lunar cycles (29.53 days x 13 = 383.9, or 384 whole days) if you allow for variance of the moon not being sighted on the 29th day (as there were no eyewitnesses to prove otherwise). With an observed calendar, it's very possible to end up with either 384 or 385 days in a year. This method, then, matches with the account given. Even if Noah could not determine the exact length of each specific month during the flood using observation, his determination would have eventually self-corrected upon confirmation of the actual lunar cycle.

This often leads to the question: where was Aviv barley to determine the new year following the flood? Genesis 8:11 describes the dove returning to the ark with a plucked olive leaf in her mouth, which seems to have served as evidence of agricultural growth (and scripture seems to include the story of the dove for this very reason). Noah may have taken this into consideration in determining the following renewed moon as being the first of the year. This same scenario often comes up regarding Israel dwelling in the wilderness following the exodus out of Egypt. Both of these situations, however, did have direct interaction by God Himself with these people and He even tabernacled with the Children of Israel out in the wilderness. He, most certainly, could have provided this information in any manner He deemed fit to keep His appointed times on schedule. What about during the Middle Ages where communication didn't exactly travel around the world as quickly as it does today. It's true that some may have relied on agricultural alternatives and, as we will learn more later, the Jews relied on a calculated 19-year timetable of historical barley cycles as an alternative after being forced out of the land. However, the truth remains that while aviv barley is available for us to reference today, which He commanded us to use, then there's no reason for us to rely on any alternatives or to change God's commandment based on hypothetical scenarios.

A second Biblical witness of a 13th month is found in Ezekiel when God asks him to demonstrate to the people their iniquities by lying on his left side for 390 days and on his right for 40 additional days. Each represented the iniquity of Israel and of Judah respectively. We are told this story begins on the fifth day of the fourth month in Ezekiel 1:1. The story continues to Ezekiel 3:16 when we are told that seven days had passed. Ezekiel 4 then describes to request of lying on each side for a total of 430 days - giving us 437 days that have passed since the date given.

Fast forward to Ezekiel 8:1 and we find Ezekiel in his house with the elders on the fifth day of the sixth month of the next year. If the year had contained only 12 lunar months, this means Ezekiel was in his house, speaking to the elders, 14 months from the date given in Ezekiel 1:1. With the average length of a lunar month, that would give us, at most, only 414 days (29.53 x 14 = 413.42), well shy of the 437 days described. If, however, there were a 13th month in that year, we would have a total of 15 lunar months that had passed - giving us 443 days (29.53 x 15 = 442.95). This would have been enough time to have completed the events described with Ezekiel sitting with the elders in his house up to six days later. With a 12-month year, these dates could have never happened unless the elders were meeting outside of his home while he laid on his side.

Finally, both of these examples prove that the length of the Biblical Year must fluctuate beyond the standard 365.24 days per year we currently observe today. They also debunk the fixed 364-day calendar contained within the pseudepigraphal (non-canonical) Book of Enoch that starts again with each Spring Equinox, amongst other theories.

The Equinox

There are other arguments that claim the Bible supports use of the Fall Equinox (or the equilux - a definition used in the Enoch calendar that indicates equal day and night in Jerusalem). Many refer to the Hebrew word tquwphah, used by Moses in Exodus 34:22[1]:

The argument is if this is referring to the Fall Equinox, then the year must begin with the Spring Equinox, another preference when applying our mathematical bias. Even though we have already seen direct instruction from Yehovah to Moses that the renewed moon of the aviv was to be the first month, the mere possibility that the equinox is referred to in scripture opens up a new Biblical variable to support calculation. The Hebrew meaning of the word tquwphah (Strong's 8622[3]) is:

Therefore, the best meaning would be full circuit or complete revolution. Psalm 19:6[1] also uses this word in relation to the cycle of the sun:

This is referring to the daily cycle of the sun from an observer's perspective - there is no further detail given here, or anywhere else in scripture, to specify the annual celestial equinox. This same Hebrew word is also used to describe the time of year kings go to war (II Chronicles 24:23) and for the cycle of pregnancy (I Samuel 1:20). Therefore, its meaning in Exodus cannot specify Fall Equinox. There is simply not enough detail given to support this concept within the context and is merely being assumed. Many will still argue that the Spring Equinox can be observed empirically. For example, you can place a stick in the ground and study its shadow throughout the year. But just watching this shadow would mean nothing of itself without further contemplation of how the celestial objects are shaped, ascertaining the complex anatomy of the Earthly equinox in relation to its orbit around the sun, the consistency of these shadows from year to year (through repeated observation over time), and finally a complete willful ignorance to God's direct instruction in Exodus to use aviv. Even though the equinoxes could be referred to as tquwphah's, most tquwphah's are not equinoxes. The context of Exodus 34 is given in verse 23[1]:

The context here is referring to the pilgrimage harvests throughout the year. These harvests are a repeating event every year and end with the wheat harvest in, what we now call, the fall season.

That being said, some also refer to star constellations, such as Pisces, that occur at the time of the vernal equinox that many use to determine when spring begins and keeping with Genesis 1:14 of using the ordained sign of the stars. In combination with the requirement that Passover take place in the spring, the rule used is to count a month as the first of the year if it causes the 14th (Passover) to fall on or after those constellations indicate the time of the equinox. Again, too complicated of a task to not be mentioned within scripture. Based on my own experience, Passover has always ended up falling after the equinox, however it has also landed in April with Passover landing a month later than the equinox. In either case, this method should not trump that of physical barley as it is not specified within scripture and cannot be supported. It also is a future event that must be calculated or predicted at the time of the renewed moon, the event from which we are already commanded to begin counting to the Passover and not to predict.

Overcoming Our Bias

It is a disadvantage to many of us today who ignore agriculture as a natural sign of timing and weather conditions. In these modern times, we rely mostly on mathematical formulas to predict seasons (usually based on the calculated equinox or equilux). In the past few hundred years, many relied on almanacs to help predict seasons and assist farmers in planting at the right times. Although these almanacs were based on mathematics, many considered them to be more accurate as they factored in specific elements such as sunrise and sunset, weather, tides, and so forth with respect to time. In other words, the math was more closely based on an observer's perspective. Even city dwellers recognized the accuracy of such publications over that of local meteorologists when it came to long-term forecasts. But even the readers of such almanacs would often fall prey to the desire to predicting such events.

The fact remains that a mathematical calendar simply cannot provide the flexibility of knowing when crops will be ready to harvest. As the saying goes, "actual results may vary". Many will feel that using the Biblical Signs for a calendar is extremely unreliable and find it difficult to break free from their comfort zones. The challenge came when the people left the Promised Land and were no longer able to observe the barley growth. This led to the decision to mathematically average the observed cycle. The long-term result, however, has led many to turn to the Hebrew calendar that uses this average method and completely ignore the instructions given to them by Yehovah Himself when the opportunity to observe barley, once again, from the Promised Land became possible again. We'll discuss this further as we begin to see how the Hebrew Calendar has developed throughout history.


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