Some 2,600 years in the past, troopers stationed at a modest navy outpost on the southern border of the Kingdom of Judah relied on a classy calendar system to trace and handle their provides, in response to a brand new examine of about 100 inscribed pottery sherds (ostraca) unearthed at Tel Arad within the Sixties.
Israeli archaeologists Dr. Amir Gorzalczany of the Israel Antiquities Authority (IAA) and unbiased researcher Dr. Baruch Rosen reanalyzed the trove of historic correspondence, specializing in the numerical knowledge — a component they argue had been largely neglected in earlier analysis.
Their findings had been just lately printed within the 2025 quantity of the Jerusalem Journal of Archaeology, a peer-reviewed publication launched in 2021 by the Hebrew College of Jerusalem’s Institute of Archaeology.
“Whereas Biblical Hebrew literacy has been broadly studied, numeracy — the cognitive capacity to grasp and manipulate numbers — stays a largely neglected, underexplored area,” Gorzalczany and Rosen write within the paper. “This text addresses this hole by analyzing the Arad Ostraca.”
“These texts had been produced within the early Sixth century BCE and concern routine administrative operations, together with issuing, receiving, and recording items resembling wine, bread, and grain,” they add. “We pay shut consideration to timekeeping techniques, together with references to days, months, and a single regnal yr.”
Analyzing the dates recorded within the inscriptions — which comprise six or seven references to the phrase month (hodesh) and 9 to day (y[o]m within the historic Hebrew script) — Gorzalczany and Rosen suggest that the troopers adopted a 30-day calendar divided into six-day intervals to manage their provide cycle.
Inscriptions in historic Hebrew relationship again 2,600 years found close to Arad. (Tel Aviv College/Michael Kordonsky, Israel Antiquities Authority)
The folks of the shard
The Arad ostraca served as on a regular basis correspondence amongst navy provide officers and had been largely addressed to a person named Elyashiv, believed to have been the fortress quartermaster across the time of the Babylonian conquest — the early Sixth century BCE, the shut of the interval referred to as the Iron Age or First Temple Interval (1200-586 BCE).
Previously decade, students have revisited these artifacts utilizing superior imaging applied sciences, uncovering beforehand invisible texts and analyzing handwriting to find out the variety of scribes concerned. Their findings reveal that, regardless of the outpost’s small garrison of simply 20 to 30 troopers, a number of scribes had been at work, indicating a far higher level of literacy in biblical Judah than beforehand assumed.
“We’re a working outpost the place items had been acquired and distributed, and one of many key methods they stored time — like many historic cultures — was by following the moon,” Rosen informed The Occasions of Israel in a telephone interview. “When the moon seems, a brand new month begins; when it disappears, the month ends. Counting months by the moon is easy, and we see the phrase ‘month’ seem seven occasions within the ostraca.”
“The day, too, is comparatively simple to trace, from daybreak to sunset or daybreak to daybreak,” he added. “At Arad, meals rations had been distributed in response to particular days, and the quartermaster appears to have adopted a set schedule for these allocations.”
Excavations at Tel Arad within the Negev Desert had been seen on March 16, 2006. (CC BY-SA Wikimedia commons)
In keeping with Rosen, the power to govern numbers at that time in historical past was fairly exceptional.
“On the twenty-fourth of the month, Nahum gave oil,” reads Ostracon 17.
“…for the tenth of the month… till the sixth of the month… and write on the second…” reads Ostracon 7.
Drawing on the times recorded within the inscriptions, Gorzalczany and Rosen recommend that the month was additional subdivided into distinct time intervals.
“If a seven-day week existed in Arad, it was probably changed by a six-day cycle, which divided the 30-day month into 5 segments, facilitating foodstuffs calculations,” the researchers write within the paper. “Such a calendrical system would have enabled each storekeepers (e.g., Eliashib) and recipients (e.g., the Kittiyim) to plan and handle provisions extra successfully by distinguishing, for instance, between perishable.”
A collage together with the verso of Arad Ostracon No. 16. (A) coloration (RGB) picture; (B) MS picture comparable to 890 nm; (C) handbook drawing (facsimile) of the proposed studying. Hole shapes signify conjectured characters. (Courtesy Tel Aviv College)
An administrative yr of 360 days divided into 12 (30-day) months was employed in historic Mesopotamia for governmental and organizational functions.
Time is relative
In keeping with Tel Aviv College’s Prof. Jonathan Ben-Dov, an knowledgeable on historic calendars who was not concerned within the examine, a comparable schematic calendar was likewise utilized in First Temple Interval Judah, coexisting with the normal luni-solar calendar for different capabilities.
“It’s a bit like how banks at present calculate curiosity utilizing 30-day months, even when a month really has 31 days,” he defined in a telephone interview with The Occasions of Israel.
Prof. Jonathan Ben-Dov from Tel Aviv College. (Courtesy)
In a 2021 study, Ben-Dov proposed that Iron Age Judeans adopted a 360-day yr made up of 12 (30-day) months, additional divided into 10-day “weeks.”
His idea attracts on biblical references — significantly the frequent use of the time period “asor” (a block of 10 days) — in addition to archaeological proof, together with 9 perforated plaques found at a number of Judean websites relationship to the center a part of the Iron Age. Most of those plaques characteristic three rows of 10 holes every, which Ben-Dov argued served as calendar instruments for monitoring the passage of time.
“I used to be not conscious of the concept of six-day items. It sounds fascinating,” Ben-Dov stated. “Nonetheless, proof for that continues to be tentative. The time references on the ostraca are sometimes fragmentary, and as I perceive it, the authors themselves current it solely as a risk slightly than a agency conclusion.”
On the identical time, Ben-Dov famous that whereas the schematic calendar could have been used for administrative wants through the Iron Age, Israelites and Judeans adopted the a luni-solar calendar to mark their religious and civil yr — a follow that didn’t set them other than their neighbors.
“In the course of the Iron Age, Israelites and Judeans had been utilizing a luni-solar calendar primarily based on moon commentary,” he stated. “However this was nothing revolutionary. If the Babylonians had been already utilizing such a system in 3000 BCE, then the Judeans might definitely have completed so by 700 BCE.”
Immediately, Jews proceed to observe a luni-solar calendar, however not depend on direct commentary of the moon, because of a calculation system developed as early because the 4th century CE, in response to some students, or later through the Center Ages, in response to others.
Illustrative: An illuminated manuscript of the Mishnah, a part of the Palatina Library’s De Rossi assortment, dated to the eleventh century. (Courtesy: Nationwide Library of Israel)
Ben-Dov defined that through the Iron Age, the calendar had not but turn into a defining characteristic of Jewish identification — a task it could assume later, starting within the Roman interval from the first century BCE onward.
“Once you have a look at later Judaism, within the time of the Mishnah [compiled in the first centuries CE], the calendar and the way it functioned is a serious focus,” he stated. “Again then, Jews emphasised that they used a lunar calendar, in distinction to the Romans’ photo voltaic calendar. In the course of the Iron Age, it merely wasn’t an enormous deal; Israelites and Judeans had been doing a lot the identical as their neighbors.”
“Biblical sources don’t specify what sort of calendar was used,” he added. “To me, that signifies it was purely a technical matter, not a foundation for identification. Later [as seen in the discussions on Rosh Hashana, the Jewish New Year], the Mishnah elevates the calendar to a core precept of religion.”
