process of trial and error in which mathematical astronomy played but a
minor part.^127
To gain an understanding of this gradual, developmental process, the results
of our investigation are tabulated in Table 2.7. In this table, different interca-
lation schemes are assigned to specific periods that tend to coincide, signifi-
cantly, with specific dynasties and reigns; but many of these periods overlap
with one another. This partially reflects our own uncertainty as to when
exactly, for example, the 3–2½-year interval scheme was abandoned in favour
of the eight-year cycle, or when the eight-year cycle was superseded by the
loose 19-year cycle (if indeed, in this case, there ever was an eight-year cycle;
all this has been discussed above). But the overlaps in this table also reflect,
more importantly, theobjectivedifficulty in identifying transitions from one
intercalation scheme to the next, since during the periods of overlap it could be
said that both schemes were simultaneously in use. Indeed, in many cases the
Babylonians themselves may have been unsure whether, or unaware that, they
were in the process of switching from one scheme to another. Thus, the years
of overlap should best be regarded as indeterminate transition periods. It is
through these transitions that the 19-year cycle of the Saros Canon was
eventually formed.
It stands to reason that the gradualfixation of the intercalation was a
process led by the kings—who had always been invested with control of the
Table 2. 7 .Intercalation schemes in the Babylonian calendar
Period Dominant reigns Intercalation scheme
7th c.BCE–537/6 Neo-Babylonian dynasty nonea
536/5–519/8 Cyrus, Cambyses 3 – 2½-year intervals in alternation
533/2–503/2 Cambyses, Darius I 8-year cycle (loose, then rigid)
525/4–465/4 Darius I, Xerxes Loose 19-year cycle
464/3–411/10 Artaxerxes I, Darius II Rigid 19-year cycle (with only XII 2 )
425/4– 141 BCE(?)b Darius II–end of Seleucid rule (?) Saros Canon 19-year cycle
141 BCE–early 3rd c.CE Parthian dynasty?
aExcept for the reign of Nabopolassar (625–604); see Table 2.1.
bThe evidence becomes very patchy after 178/7BCE.
Note:The purpose of the middle column is to show that specific intercalation schemes were often linked to
specific kings. This column names the dynasties or kings whose reign occupiedmostof the relevant period,
but often ignoring thefirst few years of the period: for example, the third row covers the period of 533/2-503/
2, but omits referring to Cyrus (although he was still reigning in the late 530s), on the assumption that
although the intercalation scheme (eight-year cycle) may have already started in the late 530s, in these early
stages it would not have been regarded as formally established.
(^127) The relationship between calendar regulation and astronomy has generally been over-
stated. It is certainly absurd to argue, as many have done, that the development of Babylonian
astronomy itself was motivated by an urge to regulate the calendar: indeed, planetary and stellar
astronomy, which dominate Babylonian astronomy, have no relevance to the lunar calendar
(Brown 2000: 170 and n. 195).
The Babylonian Calendar 119