result of being based not on empirical lunar observations, but on an abstract
scheme that appears to have been modelled on the 364-day year, as I shall
briefly explain.
Qumran calendar texts list only two days of the lunar month. Thefirst is not
named but identified as‘day 29’or‘day 30’(distinct from the day number of
the 364-day calendar month on which this day 29 or 30 happens to fall), which
clearly represents the last day of a lunar month: indeed, 29 or 30 days is the
typical length of lunar months, and in the Qumran calendars, this day occurs
regularly at intervals of 29 or 30 days in alternation. Scholars refer to this
unnamed day (‘ 29 ’or‘ 30 ’)as‘x’. The second lunar day (only attested in
4Q321–321a) is calledduqah, and always occurs 13 days before x, i.e. one or
two days after the midpoint of the lunar month. The meaning of the word
duqahhas been much debated, as well as whether the lunar month assumed in
Qumran calendars began at the new moon or at the full moon (or on the
following day); these debates are all interrelated, and beyond our scope.^16 But
those uncertainties aside, the lunar calendar implicit in x alone can easily be
reconstructed as a scheme of 29- and 30-day months in alternation, with the
intercalation of an extra 30-day month every three years, which amounts
exactly to three 364-day years. This results in a three-year lunar cycle, which
when doubled can be synchronized, most conveniently, with the six-year cycle
of priestly courses. The very neat compatibility of this lunar calendar with the
364-day year suggests that it was arithmetically constructed on the basis of,
indeed derived from, the 364-day calendar.^17 This came, however, at the cost
of astronomical accuracy. The regular alternation of 29- and 30-day months
(^16) See Beckwith (1992) 462–4,Wise (1994) 222–32, VanderKam (1998) 60, 79, and 85–6,
Gillet-Didier (2001), Talmon, Ben-Dov, and Glessmer (2001) 13–14, 33–6, 209–10, Ben-Dov
and Horowitz (2005), and Ben-Dov (2008) 215–37. Most scholars (VanderKam, Gillet-Didier)
interpretduqahas the new moon crescent, and hence the beginning of the month at the full
moon, which would be uncharacteristic of ancient Near Eastern and Mediterranean lunar
calendars. A month beginning at the new moon (Beckwith,Wise, Talmon) would better explain
why the three-year lunar cycle in Qumran calendar texts begins on day x, which on any
interpretation is thelastday of a lunar month: if the month began at the new moon crescent,
day x could have represented the conjunction, which would have been a good point for a
schematic lunar cycle to begin. This theory, however, has more difficulty explainingduqah,
with would correspond, rather strangely, to one or two days after full moon. Ben-Dov and
Horowitz rescue this theory in a modified form, by interpreting x andduqahas astronomical
annotations drawn from Mesopotamian traditions, whereby x = KUR refers to the last morning
of lunar visibility at the end of the lunation, andduqah= NA refers to thefirst moonset occurring
after sunrise on the day following full moon. 17
This follows Ben-Dov’s argument (2008: 119–51) that the 364-day calendar,first attested in
the 3rd-c.BCEAstronomical Book of Enoch, preceded and formed the basis of the Qumran
triennial lunar calendar, only attested later in the mid-2nd-c.BCEcalendar text 4Q317 and then
later still in 4Q320, 321, and 321a (late 2nd–1st cc.BCE), where it became synchronized with the
priestly courses. Ben-Dov aptly concludes:‘while lunar phenomena were taken into account in
calendar reckoning, they were recognized in order to synchronize them with the 364-day
year...The moon was no longer considered to be a physical object which moves in a complex
orbit in the sky, but a“theoretical”object that behaves according to simplistic, linear, and
Sectarianism andHeresy 365