ChangeIn other ways, however, the calendars of post-Seleucid city states and king-
doms developed their own, distinctive characteristics and drifted away from
their Seleucid matrix. The main factor in this process was intercalation. It
seems that once kingdoms and cities broke loose from the Seleucid Empire,
they did not consider themselves bound to the strict observance of the
Babylonian 19-year cycle. A single change in intercalation was sufficient to
create a one-month discrepancy from the Seleucid calendars; the resulting
fragmentation and differentiation of calendars could become, therefore,
significant.
Among the earliest to have deviated, in this manner, from the Babylonian
19-year cycle was the kingdom of Pontus (along the south of the Black Sea).
Actually, Pontus had never really been part of the Seleucid Empire, for it had
already emerged as an independent kingdom already at the end of the wars of
the Diadochi, by the beginning of the third centuryBCE. But it had previously
been part of the Achaemenid Empire, when it presumably used the official
Babylonian calendar; and in the Hellenistic period, the kingdom of Pontus is
known to have used a Macedonian calendar.^38 One might have expected this
calendar to have been assimilated to the Babylonian calendar, just as it was in
the neighbouring Seleucid Empire. In the kingdom of Pontus, however, inter-
calations differed from those of the Babylonian calendar. Numismatic evi-
dence from earlyfirst-centuryBCEPontus reveals that a thirteenth month was
intercalated in 90, 88, and 74BCE;^39 whereas in the Babylonian calendar, we
know from an astronomical diary that an intercalation was made in 87BCE.^40
The most important post-Seleucid state in the proper sense of the term was
the Parthian kingdom; not much is known about its calendar until the mid-
first centuryBCE, when numismatic evidence of month-names becomesfirst
available. Analysis of this evidence has been marred by the assumption that
Parthian intercalations conformed to the Babylonian calendar, but this is
(^38) Two 2nd-c.BCEPontic inscriptions are dated to the Macedonian months of Daisios and
Dios: Callataÿ (1997) 29–30. The early-1st-c.BCEnumismatic attestations of a 13th month
(discussed below) con 39 firm that the calendar was lunar.
Ibid. 39, 43, and 48 respectively. This follows Callataÿ’s preferred dating of the Pontic era as
beginning in 297/6BCE, hence year 207 (Pontic era) is 91/0BCE. The alternative, that the era began
one year earlier, would place year 207 in 92/1BCEand 209 in 90/89BCE(ibid. 30–2).
(^40) See Ch. 2, Table 2.6 and n.c: this was in the spring, i.e. second Addaru (XII 2 )87BCE.
Callataÿ assumes that the Pontic intercalations were made in the autumn, on the grounds that
the year probably began in Dios, following Macedonian usage, and that intercalations were made
at the end of the year (ibid. 29–30). If Callataÿ is right (and indeed, this remains the most
plausible theory), the discrepancy from the Babylonian calendar would have been of six months;
if Pontic intercalations were made earlier in the year, e.g. in the spring, the discrepancy from the
Babylonian calendar would have been of one year. If we assume the alternative dating of the
Pontic era (see previous n.), the Pontic intercalation would have been in (autumn) 89BCE, thus a
discrepancy of one and a half years from the Babylonian calendar.
248 Calendars in Antiquity