A common source for the late Babylonian chronicles dealing with eighth andseventh centuries

The nature of the sources of the Babylonian chronicles remains a matter of controversy even after decades of occasional discussion. Here statistical e vidence is presented that the sources of the chronicles dealing with politi cal events up to the time recorded in Chron. 2 were astrological texts. The number of coincidences between exact dates in the examined chronicles and an adannu of 30 days after the ominous planetary events is compared to the number that can be expected in a random sample of dates between 750-600. Th e null-hypothesis that the number of coincidences found in the chronicle sa mple is random could be rejected at a safe p < 0.02. The long-sought "commo n source" of the late Babylonian chronicles dealing with the eighth and sev enth centuries was therefore in all probability a corpus of astrological te xts. Chronicles dealing with later times were compiled from texts of a diff erent nature. This shift from one kind of source texts to another makes a d iachronically differentiated approach in the evaluation of the information contained in individual chronicles imperative. The design of the proposed t est necessitates a sound basis for finding the possible Julian equivalents of Babylonian dates. A reanalysis of New Year's dates inferred from the ecl ipse data in LBAT 1413-1417 and of New Year's dates between 626-539 is ther efore presented in the first part of this paper. An average beginning of th e year two weeks before equinox is demonstrated to be probable only until 7 30. From that time to the end of Nabopolassar's reign a constant ratio of - 7 intercalations per 19 years was maintained, which kept the average Babylo nian New Year's date a few days before equinox. Only at the turn to the six th century can a second shift to even later dates be demonstrated.