the political and religious status which astrologers held in Mesopotamian
society, together with their astronomical expertise, explain how they came to
exercise such authority over the calendar in a way that was second only to the
king. But they still remained directly answerable to the king, and it was to the
king that all calendrical decisions were ultimately referred. The‘scientific’
character of the Babylonian calendar was thus overshadowed, in several
respects, by the overriding force of social and political authority. As I shall
argue, the regularization of the Babylonian calendar in thefirst millenniumBCE
was largely the outcome of political factors, such as its use as official calendar
in increasingly expanding territorial empires.
There is no explicit description of the calendar in extant Mesopotamian
cuneiform sources,^8 but administrative and economic documents, and more
importantly astronomical texts, provide us with a large amount of data on the
Babylonian calendar, far more than is available for Greek calendars. Conse-
quently, our study of the Babylonian calendar will differ considerably, in
method and approach, from that of the Greek calendars. Substantial evidence,
administrative as well as astronomical, only begins in the neo-Assyrian period
(eighth–seventh centuries) and lasts until thefirst centuryBCE. This chapter
will focus on this period, with only occasional references to earlier origins;
later developments of the Babylonian calendar and its derivatives will be
examined in Chapter 5.
The use of astronomical sources for the study of the calendar raises meth-
odological problems which cannot be ignored. Many astronomical sources are
known to have been theoretical and predictive; the calendar they assumed was
only a projected future time frame, which might differ from how the calendar
was eventually reckoned in practice. Considerable care needs to be exercised,
therefore, when using these sources as evidence of how the Babylonian
calendar was reckoned in Mesopotamian society.^9 But a large number of
astronomical texts, referred to in modern scholarship as‘Astronomical Dia-
ries’, contain reports of actual astronomical observations. It is unlikely that the
calendar assumed for dating these observations was a theoretical‘astronomical
calendar’, because the regularity with which dated astronomical observations
officials (cf. Jer. 51: 27), and these astrologers were certainly far more than scribes. The
professional identity of the astrologers was complex; my use of the term‘astrologers’should
not be taken to mean that astrology (or astronomy, a distinction that was not clearly made) was
their sole function or area of expertise. See further Parpola (1970–83) ii, p. xiv, Rochberg (2010),
and Geller (2010).
(^8) This may explain why relatively little attention has been given to the Babylonian calendar in
modern scholarship (with some notable exceptions, e.g. Beaulieu 1993, Steele 2007), by compar-
ison with the well-established tradition of scholarship on Babylonian astronomy. 9
This will restrict our use e.g. of Saros Canon texts for charting the intercalated years.
74 Calendars in Antiquity