Babylonian astronomical diaries

These are classified as the third category of Babylonian astronomical texts, alongside the Astronomical Cuneiform Texts published by Otto Neugebauer and Abraham Sachs and GADEx, sometimes called “non-ACT” by Neugebauer.

The Babylonians were the first to recognise that astronomical phenomena are periodic and to apply mathematics to their predictions.

At the end of each month, the Diaries report the river level of the Euphrates; the market exchange values of several commodities in Babylon, and sometimes selected historical events such as warfare, disease outbreaks, visits from kings or officials, and cultic activities.

The Diaries contain no explicit indications of purpose, but since they exhibit significant parallelism with prognostic material, it is likely that they were connected to some extent with divination.

In addition to the evidence they offer about Babylonian astronomy, the Diaries are the main contemporary source for the political history of Late Achaemenid and Hellenistic Babylonia, while their records of commodity values provide exceptionally detailed and extensive economic data.