The major cities of Babylonia possessed, at least by the end of the fourteenth century B.C., hemerologies which indicated, for each month of the year, which days in that month were regarded as propitious. In the time of Nazimaruttash, king of Babylon, whose reign covered the turn of that century, the versions of Sippar, Nippur, Babylon, Ur, Larsa, Uruk, and Eridu were collated and excerpted to produce a single version, which was presumably regarded thenceforward as the standard version for Babylonia.
This standard version (preceded by a longer text of a rather different kind, which indicated which months of the year were regarded as favourable for the performance of various specified actions, such as founding a palace, changing one's occupation, or falling from a roof) was later—perhaps some two centuries later—set out on a large tablet since found in the remains of the city of Ashur, and was followed on the tablet by a further version, by no means in complete agreement with the standard version, and identified on the tablet as the Ashur version.
To these two versions of the short summary hemerology for the whole year, however, the tablet adds two sets of special very detailed instructions for the first eight days of the seventh month of the year, Tashritu; the first set (to which are prefixed short instructions for certain days of the first month, Nisanu) is described on the tablet as the Ashur version, while the second (a shorter set, differing extensively in detail from the Ashur version, and without prefixed instructions for Nisanu, but including, additionally, special instructions for the ninth day of Tashritu) is marked as the Akkad version.