- THE BEGINNING OF THE MONTH
The new moonIt is generally agreed that the Babylonian month began, in principle, when the
new moon crescent wasfirst visible and sighted. Although explicit evidence is
lacking—there are few, if any, explicit statements in the sources that the
evening of the 1st of the month was when the new moon was eitherfirst
visible orfirst sighted—indications to this effect are very clear.
The assumption, or perception, that the month began at thefirst appearance
of the new moon can be traced back to the origins of Babylonian civilization.
In the lunar festivals such as theeššešu(attested from the end of the third
millennium until the neo-Babylonian period), full moon celebrations were
held on the 14th or 15th of the month; this suggests that celebrations on the
1st of the month would have been intended to mark the new moon’sfirst
appearance.^12 In the Creation epicEnuma Eliš(tablet 5), the god Marduk tells
the moon that it will be full on the 15th and in conjunction on the 30th—
which impliesfirst visibility on the 1st.^13
Sources from the sixth–first centuriesBCEconfirm that the new moon was,
by and large, when Babylonian months actually began. The Astronomical
Diaries report a range of observed astronomical events (lunar, planetary,
and/or stellar) and date them according to the Babylonian calendar.^14 They
do not mention explicitly thefirst appearance of the new moon, but they do
provide, as a standard entry, the time-lag between sunset and moonset on the
first evening of the month. Modern astronomy enables us to calculate when
this time-lag would have occurred, and hence, the equivalent Julian date of the
first evening of the Babylonian month.^15 In the vast majority of cases, this date
is when (again, according to modern astronomy) the new moon would have
beenfirst visible (Stern 2008). The same procedure can be applied to other
entries in the Astronomical Diaries, which can be similarly astronomically
dated. Since these entries are dated in the texts according to the Babylonian
calendar, it is possible to establish, by working back to the beginning of the
month, that the Babylonian month began on the evening when the new moon
(^12) See Brown (2000) 113–14, 248. If the full moon occurs on the 14th or 15th of the month,
the month can only begin atfirst visibility of the new moon (see e.g. Stern 2001: 130).
(^13) Pritchard (1950) 67–8; Brown (2000) 235, 253; Steele (2007) 133–5. For the meaning of
‘conjunction’see Ch. 1, near n. 6.
(^14) The Astronomical Diaries extend from the 8th to 1st cc.BCE(but mainly only from the 6th
c.BCE), and are thought to be almost all from the city of Babylon; they have been edited,
translated, and astronomically dated by Sachs and Hunger (1988–2006). Some of this material
was only preserved in later (and sometimes much later), Seleucid- or early Parthian-period
compilations, but there is no reason to doubt its authenticity. For a general introduction see
Hunger (1999). 15
This procedure is known as‘astronomical dating’: Sachs and Hunger (1988–2006) i. 19.
76 Calendars in Antiquity