Beaulieu has recently suggested that the festival which ancient sources connect with the fall of Babylon in 539 BC may have been an akītu festival in honor of the moon god Sîn. This proposal can be supported by two additional arguments. First, the dates of the festival (the 16th and 17th of Tašritu) would always have come immediately after the Harvest Moon or Hunter's Moon. Second, a Mesopotamian akītu festival celebrated in Tašritu and dedicated to the moon god appears to be the background of the Aramaic liturgy preserved in Papyrus Amherst 63. Given the religious politics of Nabonidus' last years, in which Sîn was promoted at the expense of Marduk, it is likely that a similar akītu festival took place in Babylon at the time of its fall.