A FIRST DESCRIPTION OF THE ISRAELI BARLEY OBSERVATION DATA

by ALEX STRASHNY

 

INTRODUCTION

OBSERVATIONAL CALENDAR

The Hebrew calendar is often described as “lunisolar” because the length of the calendar month is approximately equal to the lunar (or synodic) month of about 29.5 days, while the average length of the calendar year is approximately equal to the solar (or tropical) year of about 365.25 days. Since the length of the solar year is not divisible by the length of the lunar month, this is achieved by intercalation – the insertion of a leap month. Thus, regular calendar years have 12 months, while leap years have 13 months.

The fixed Hebrew calendar that we use today is traditionally attributed to Hillel II, who lived in the 4th century CE. The description of the calendar as “fixed” indicates that the calendar is calculated and does not use observations. According to rabbinical sources, prior to the introduction of the fixed calendar the Hebrew calendar used a combination of observations and calculations. There were many factors involved in determining when the year should be intercalated.

Talmudic sources report that the calendar council intercalated a year when the barley in the fields had not yet ripened, when the fruit of the trees had not grown properly, when the winter rains had not stopped, when the roads for Passover pilgrims had not yet dried up, and when the young pigeons had not become fledged. The council considered the astronomical facts together with the religious requirements for Passover and the natural conditions of the country.1

One of the rules of intercalation was that by the beginning of the first month (Nisan), barley had to be ripe enough. If it was not ripe enough by the end of the 12th month (Adar), then a 13th month (Adar Bet) was added. Rashi on Deuteronomy 16:1, based on TB Sanhedrin 11b, explains: “Observe the month of spring [aviv]: Before it [Nisan] arrives, watch that it should be fit for the aviv ripening [capable of producing ripe ears of barley by the sixteenth of the month], to offer up in it the omer meal offering. And if not, proclaim it a leap year [thereby enabling you to wait another month, until the barley ripens].” 2

Deuteronomy 16:1 is one of several verses that calls the first month “the month of aviv” (also sometimes transcribed as abib). According to Rashi, by Nisan 16, when the omer offering of barley is made, barley has to be ripe and ready to harvest. Therefore, before the beginning of the first month, barley has to be in a state of its ripening which is called “aviv.” This is a state close to full harvest-ready ripening. If, by the end of the 12th month, barley is not yet aviv, then a 13th month is added.

Exodus 9:31-32 explicitly refers to aviv as a stage of barley ripening. In describing the plague of hail, the verses say: Now the flax and barley were ruined, for the barley was in the ear [aviv] and the flax was in bud; but the wheat and the emmer were not hurt, for they ripen late. Rashi on 9:32, explaining why wheat and emmer were not broken, writes “they were still tender and were able to withstand the hard [hail]”. Regarding the aviv state of barley, Rashi on 9:31 writes “it has already ripened and is standing in its stalks, and they have been broken and have fallen”. In other words, aviv is the stage of barley ripening when it is no longer tender, but hard, and so is capable of being broken by hail.

One key passage in the Talmud that explains some of the rules of intercalation is found on TB Sanhedrin 11b. According to the passage, a 13th month was added if two of these three conditions were true: (1) barley was not yet aviv by the end of the 12th month; (2) it was seen that, with only 12 months in the year, the fruits of the trees would not ripen in time for Shavuot; and (3) it was seen that, with only 12 months in the year, Passover would occur before the March equinox. The passage also mentions that the people searched for aviv barley in three regions – Judea, Transjordan, and Galilee.

A discussion of the requirement regarding the fruits of the trees, based on Numbers 28:26, is beyond the scope of this paper. The requirement regarding the March equinox was to make certain that Passover occurs in the Spring. The Torah itself does not say anything regarding an equinox. In principle, the ripening of barley is already governed by the seasons, which in turn are governed by the sun,3 and so the equinox requirement should normally not come into play.

ANNUAL AVIV SEARCHES

Starting in 1988, Nehemia Gordon, who holds a Master’s Degree in Biblical Studies from the Hebrew University of Jerusalem, has been organizing and leading annual searches for aviv barley in Israel.4 As far as we are aware, these are the first such searches in modern times.

This paper intends to bring the aviv searches, including the specific definition of aviv that Gordon and his teams use, to wider public attention. For the first time in a peer-reviewed publication, we present and describe the annual data from these searches. This data could be used for further research into the relationship between the fixed and observational versions of the Hebrew calendar.

While the calendar rules under the Talmudic system were complicated, for the purposes of this paper, in order to showcase the potential usefulness of the aviv searches for the Hebrew calendar, we define a hypothetical observational version of the calendar as follows – sightings of the new crescent moon from Israel determine the beginning of the month; the first month after aviv barley is found in Israel is considered the first month of the year.

 

METHODS

DETAILS OF THE AVIV SEARCHES

The early aviv searches involved a lot of learning about how to find aviv barley in practice, producing results thought to be unreliable.5 The first results which were considered reliable and were reported to the public are from the year 2000.

The aviv search teams examine “all three types of barley that grow in Israel: 2-row wild barley, 2-row domesticated barley, and 6-row domesticated barley”, “both volunteer barley and planted fields”.6 The searches are performed throughout Israel, including in the following areas: Judaean Mountains, Shfela, Northern Negev, Judean Desert, Jordan Valley, Beth Shean Valley, Jezreel Valley,7 the areas near Jerusalem,8 the Israeli coastal plain, the Upper Galilee, the Lower Galilee, and the Hula Valley.9

People from around the world come to participate in the aviv searches, including from Israel, the United States, England, and South Africa.10 Of particular note is Ruthanne Koch, a Certified Crop Adviser from the United States,11 who has participated in and provided agricultural advice to the aviv search teams for several years.

 

DEFINITION OF AVIV

In order to actually look for aviv barley, Gordon has developed a specific definition of what aviv means in modern agricultural terms. According to Gordon, using modern agricultural terminology, barley goes through seven stages of development. The sixth stage, called the “wax stage,” is thought to be aviv. Here is a list of all seven stages of the development of barley, as described by Gordon:

  1. Grass stage: Heads (ears) have not appeared. Barley looks like tall grass.
  2. Head stage: The heads (ears) of grain have begun to appear. The seeds have not yet begun to form.
  3. Cotton Stage: The seed shells are filled with a cotton-like substance, which over time gets replaced with seed material.
  4. Water Stage: The seeds have begun to grow but when squeezed, liquid comes out.
  5. Worm Stage / Smear Stage: The seeds are forming, but when squeezed, the worm-like insides come out. In some strains of barley, the seeds never get very large and it is difficult to distinguish between the Water Stage and Worm Stage. In these species, the seeds smear when squeezed in both Water Stage and Worm Stage.
  6. Wax Stage: The seeds are fully formed and have fattened. They do not break when squeezed and are like soft wax. This stage is our working definition of aviv.
  7. The seeds are like hard wax and are ready for harvest using ancient methods.12

Enough aviv barley must be found so that, once it ripens completely, it can be brought in the omer offering during the Passover holiday, between 2 and 3 liters.13 Thus, individual stalks of aviv barley growing among barley that is not yet aviv do not count as a finding of aviv barley.14

DATA COLLECTION

Initial barley observations are typically made near the end of the 12th month. In some years, aviv barley is found on the first day of the search. If aviv barley is not found by the end of the 12th month, then additional searches are made in the following month, typically near the end of the month. Gordon announces the results of the searches as they occur using his newsletter.

In this paper, we present two Gregorian dates related to the aviv searches for each year – (1) the date of the latest search during which aviv barley was not found; and (2) the date of the earliest search during which aviv barley was found. In those years when aviv barley is found on the first day of the search, the first date is missing.

We also present the Gregorian date of the first new crescent moon observed from Israel after aviv was found. According to the hypothetical observational calendar, this is the first day of the first month (Nisan 1). According to TB Sanhedrin 11b, that is only the case if the 15th day of this month is after the March equinox. We therefore also give the Gregorian date of Nisan 15 on the hypothetical observational version of the calendar. This date is calculated as the date of the new crescent moon observed from Israel after the earliest finding of aviv barley plus 14. We compare this date to Nisan 15 on the fixed version of the calendar.

The data on new crescent moon sightings comes from the Israeli New Moon Society (INMS).15 INMS, led by Dr. Roy Hoffman of the Hebrew University of Jerusalem, and by Tuvia Kaatz, organizes sightings of the new crescent moon. The INMS data set consists of multiple monthly observations starting in 1981. Since new crescent moon observations are made in the evening, INMS data gives the Gregorian date of the evening on which the moon was actually sighted, while we give the next Gregorian date, which would be the first day of the hypothetical observational month. The post-aviv new crescent moon for 2011, 2015, and 2016 was not reported by INMS, but was reported by Gordon.

RESULTS

Table 1 shows the annual barley observation data. Specifically, it shows both the Hebrew and the Gregorian year; the date of the latest search during which aviv barley was not found; the date of the earliest search during which aviv barley was found; the date of the day after the evening on which the first new crescent moon was seen from Israel after a finding of aviv barley; the date of Nisan 15 on the hypothetical observational and fixed versions of the Hebrew calendar; and the difference between the two dates.

Table 1: Israeli Barley Observation Data, 2000 – 2016

Year Aviv dates New moon post-aviv Nisan 15 Difference
Hebrew Gregorian Latest search aviv not found Earliest search aviv found Obs. Fixed
5760 2000 March 12 April 4 April 7 April 21 April 20 -1
5761 2001 March 2 March 11 March 27 April 10 April 8 -2
5762 2002 * March 14 March 16 March 30 March 28 -2
5763 2003 March 4 March 30 April 4 April 18 April 17 -1
5764 2004 March 8 March 22 March 23 April 6 April 6 0
5765 2005 * March 8 March 12 March 26 April 24 29
5766 2006 February 28 March 28 March 31 April 14 April 13 -1
5767 2007 * March 18 March 21 April 4 April 3 -1
5768 2008 March 6 March 23 April 8 April 22 April 20 -2
5769 2009 * March 26 March 28 April 11 April 9 -2
5770 2010 * March 12 March 18 April 1 March 30 -2
5771 2011 March 22 March 30 April 5 April 19 April 19 0
5772 2012 * March 22 March 24 April 7 April 7 0
5773 2013 * March 11 March 14 March 28 March 26 -2
5774 2014 March 2 March 25 April 1 April 15 April 15 0
5775 2015 February 27 March 15 March 22 April 5 April 4 -1
5776 2016 March 10 March 27 April 10 April 24 April 23 -1

* = not available. Aviv barley was found during the first search.

Source: Israeli Barley Observation Data, 2016.

The table contains 17 years of data, from 2000 to 2016. In ten of these years, aviv barley was not found during the initial search, and therefore both a date when aviv barley was not found and a date when it was found are available. In seven of the years, aviv barley was found during the initial search; for these years, only the date when aviv was found is available.

The dates of aviv searches that did not find aviv barley ranged from February 27 in 2015, to March 22 in 2011. The median date of when aviv barley was not found is March 5 (see Table 2). The dates of barley searches that did find aviv barley ranged from March 8 in 2005, to April 4 in 2000. The median date of when aviv barley was found is March 22. Note that the earliest date when aviv barley was found (March 8) is well before the latest date in a different year when it was not found (March 22). The date of the first new crescent moon after aviv barley was found ranged from March 12 in 2005, to April 10 in 2016. The median date is March 27.

The date of Nisan 15 on the hypothetical observational calendar ranged from March 26 in 2005, to April 24 in 2016, with the median being April 10. Even the earliest date of March 26 is well after the March equinox. Thus, all of the hypothetical observational Nisan 15 dates fulfill the conditions of TB Sanhedrin 11b. In 14 of the 17 years, the observational Nisan 15 was within 30 days of March 21. However, in 2000, 2008, and 2016, the observational Nisan 15 was more than 30 days after March 21, which means that, in those years, the 15th day of the previous lunar month fulfilled the March equinox requirement of TB Sanhedrin 11b while not fulfilling the aviv requirement.

The date of Nisan 15 on the fixed Hebrew calendar ranged between the same dates – March 26 in 2013, and April 24 in 2005. The median of the fixed Nisan 15, however, is April 9, one day before the median of the hypothetical observational Nisan 15.

Table 2: Summary of the Israeli Barley Observation Data, 2000 – 2016

Event Minimum Median Maximum
Latest search aviv not found February 27 (in 2015) March 5 March 22 (in 2011)
Earliest search aviv found March 8 (in 2005) March 22 April 4 (in 2000)
New moon post-aviv March 12 (in 2005) March 27 April 10 (in 2016)
Observational Nisan 15 March 26 (in 2005) April 10 April 24 (in 2016)
Fixed Nisan 15 March 26 (in 2013) April 9 April 24 (in 2005)

Source: Israeli Barley Observation Data, 2016.

As far as the difference between the fixed and the hypothetical observational Nisan 15 – in four years, the two occurred on the same day; in six years, the fixed Nisan 15 was earlier by 1 day; and in another six years, the fixed Nisan 15 was earlier by 2 days. The median is that the fixed Nisan 15 is one day earlier than the hypothetical observational Nisan 15.

In one year – 2005 – the fixed Nisan 15 was a full month after the hypothetical observational Nisan 15. Thus, in terms of the approximate date of Passover, based on this very small data set, the agreement between the fixed and observational versions of the calendar are in 16 out of 17 years.

On the hypothetical observational calendar, the year length of the year beginning on Nisan 1 varied from 354 days to 385 days, with a median length of 355 days. This is consistent with the number of days in the fixed calendar. The year from March 2015 to April 2016 was the only 385 day year. The average year length was 365.44 days, which is close to the solar year of approximately 365.25 days.

DISCUSSION

This paper is the first presentation of modern aviv search data in a single place in a peer-reviewed journal. The publication of this data allows for further research into the relationship between the fixed and observational versions of the Hebrew calendar.

The teams, led by Gordon, have been performing annual aviv searches for almost 30 years. By now, they appear to have the practical knowledge to reliably find barley in the state of aviv. Knowing when barley in Israel is aviv is a key step in reconstructing a simple hypothetical version of the observational Hebrew calendar.

The finding that the fixed Nisan 15 is typically one day earlier than the hypothetical observational Nisan 15 makes sense because the fixed calendar uses the calculated conjunction between the Sun and the Moon (the “new moon” or “dark moon”, when the moon is not visible) to determine the beginning of the month, while the observational calendar uses the observed new crescent moon, which comes about a day after the “dark moon”.

We found one year, 2005, in which the fixed calendar and the hypothetical observational calendar are in conflict regarding the date of Passover by a month. Yaakov Loewinger, an Israeli engineer who has written a lot about the Hebrew calendar, in an abstract to one of his talks at the Jewish Calendar Seminar at Bar-Ilan University, explained what happened that year. “On Rosh ha-Shana 5765 we entered the 8th year of the 304th 19-year cycle of the Hebrew calendar. It is well-known that the intercalation of this year (and of some other years as well) poses some serious calendric problems: it seems this intercalation is not necessary in order to achieve the main objective of the Hebrew calendar, namely to cause the relevant days of Pesah 5765 to fall after the Vernal Equinox.”16

According to Loewinger, based on his study of the fixed Hebrew calendar, the 8th year in the 19-year Metonic cycle should not be intercalated, as it is unnecessary. This includes the Hebrew year 5765, corresponding to the Gregorian year 2005. Instead, if the 8th year of the cycle was not intercalated, then the 9th year would be intercalated.   If Loewinger’s opinion were followed, then, in terms of the approximate date of Passover, based on this very small data set, the fixed and hypothetical observational versions of the Hebrew calendar would be in full agreement.

 

NOTES

  1. A. Spier, The Comprehensive Hebrew Calendar: Twentieth to Twenty-second Century, 5660-5860, 1900-2100 (Jerusalem: Feldheim Publishers, 1986) p. 1.
  2. Quotes from Rashi are based on A. J. Rosenberg (editor), Complete Tanach with Rashi (New York: Judaica Press).
  3. B. Uval, “The Mosaic of Time”, Jewish Bible Quarterly 31:4 (2003), pp. 226-229.
  4. N. Gordon, “#198: Aviv Report 2005 and Related Aviv-Issue”, Karaite Korner Newsletter (March 13, 2005).
  5. Ibid.
  6. N. Gordon, “#260: Aviv Found! (corrected)”, Karaite Korner Newsletter (March 30, 2006).
  7. N. Gordon, “#125: Aviv Not Found, 13th New Moon Sighted”, Karaite Korner Newsletter (March 4, 2003).
  8. N. Gordon, “#194: Aviv Found!”, Karaite Korner Newsletter (March 8, 2005).
  9. N. Gordon, “#257: Aviv Report 2006”, Karaite Korner Newsletter (March 2, 2006).
  10. N. Gordon, “#323: Aviv Not Found, Thirteenth Month to Begin after Shabbat”, Karaite Korner Newsletter (March 6, 2008).
  11. N. Gordon, “#125: Aviv Not Found, 13th New Moon Sighted”, Karaite Korner Newsletter (March 4, 2003).
  12. N. Gordon, “#30: Aviv Report 2000 (#2)”, Karaite Korner Newsletter (March 19, 2000).
  13. Michael Coogen, ed., The New Oxford Annotated Bible (Oxford: Oxford University Press, 2001), p. 535.
  14. N. Gordon, “#323: Aviv Not Found, Thirteenth Month to Begin after Shabbat”, Karaite Korner Newsletter (March 6, 2008).
  15. Israeli New Moon Society. https://sites.google.com/site/moonsoc/
  16. Y. Loewinger, “The 8th in the 19-year Cycle of the Hebrew calendar: Another Look at ‘Al ha-Sheminit’”, Jewish Calendar Seminar (2004/2005).

Alex Strashny is a statistician. He is interested in how ancient practices, including following the observational calendar, could be performed today.