sighting (in the Achaemenid and Seleucid periods) demands an explanation. It
reflects, perhaps, increased confidence in the astrologers and the accuracy of
their new moon predictions. This increased confidence was possibly the result,
in turn, of the significant progress that was being made by Babylonian
astronomy, mainly in the Seleucid period; but it may equally reflect a change
in the socio-political status of astrologers and their authority over calendrical
decisions. Thus it is difficult to know whether calendar change was, in this
case, the result of‘scientific’progress or rather of socio-political change.
The regularization of the Babylonian month through the use of new moon
predictions may also be related to the formation and rise of the great Near
Eastern empires. As early as the neo-Assyrian period, the Babylonian calendar
was used as an official state calendar; the beginning of the month, which the
king determined, had to be transmitted in the form of‘reports’across the
Assyrian Empire—a procedure that could take several days, even within
Mesopotamia (from Assyria to Babylonia). In the vastly increased territories
of the Achaemenid Empire, the dissemination of this information month by
month became an impossibility: in remote areas such as Memphis and
Elephantine in Egypt, new moon reports were well beyond reach. This is
why the Babylonian months in Egypt had to be reckoned locally, on an
independent—and frequently divergent—basis.^74 Evidence from Idumaea
(southern Palestine),^75 and in the east, from Bactria (northern Afghanistan),^76
(^74) Evidence for this may be drawn from 5th-c. Aramaic sources from Memphis and Elephan-
tine dated according to the Egyptian and Babylonian calendars, where the Babylonian date
differs (typically by one day) from what would be expected of the central Babylonian calendar:
see Stern (2000a), also (on Memphis) Parker (1941) 297 and Porten (1990) 29; sources are in
Porten and Yardeni (1986–99). This argument is slightly speculative, however, as we do not
possess Babylonian records of new moons (e.g. in the Astronomical Diaries) for most of this
period; without them, the dates of the central Babylonian calendar cannot be established with
certainty.
(^75) This may be inferred from two Aramaic ostraca, but the evidence is weak. Thefirst is dated
30 Sivan year 46, which can only be of Artaxerxes II, thus 359BCE(Porten and Yardeni 2007: 149
no. 74); whereas the month of Sivan (i.e. Simanu) of the Babylonian calendar in 359BCEshould
have been of 29 days. The second is similarly dated 30 Sivan year 16, most probably of Artaxerxes
III, thus 343BCE(Eph’al and Naveh 1996: 56 no. 104); again, Sivan in this year should have been
of 29 days. Unfortunately, we do not have an astronomical diary (or any other Babylonian
evidence) to confirm that in either of these years, the Babylonian month had only 29 days.
Furthermore, as argued above, day-30 dates in economic documents are not necessarily indica-
tive of the length of the calendar month. 76
Evidence from Bactria isfirmer, although confined at present to one Aramaic document
dated year 2, Shebat 20, daydain(Shaked 2004: 42–5, Naveh and Shaked forthcoming). In the
Persian calendar, which was not lunar but based on a 365-day year,daināwas the name of the
24th day of the month (see Chapter 4 and n. 62). The nearest (and indeed, the only possible)
equivalence of Shebat:20 todaināof any Persian Zoroastrian month in any year 2 of the
Achaemenid period is in the reign of Artaxerxes III (in 357/6BCE), whendaināof Isfandārmuä
(the twelfth month of the year) is expected to have coincided with 22 Shabat:u of the Babylonian
calendar. This datingfinds further confirmation in that the document belongs to a batch from
the late Achaemenid period, and that the document refers to offerings for the spirits of the dead
(prwrtn), which were honoured during the epagomenal days following the twelfth month of the
The Babylonian Calendar 93