The Nonintercalated Lunar Calendar of the Middle Assyrian Period

Abstract

Scholars generally assume that Assyria employed a luni-solar calendrical system during the Middle Assyrian period—akin to the one used in Babylonia—that kept the months of its year synchronized with the seasons of the solar year through periodic intercalation. With this understanding, the regnal dates assigned to the Middle Assyrian kings have traditionally been expressed in terms of solar years. The present article, however, argues that the Assyrians did not use this type of system. The author draws upon a variety of administrative tablets—primarily from the reigns of Shalmaneser I, Tukultī-Ninurta I, and Tiglath-pileser I—to demonstrate that the months of the Assyrian year were in fact not permanently affixed to particular seasons of the solar year, revealing that its year was not intercalated and was thus perpetually rotating slowly through the solar year. This article also explores how such a calendrical system impacts the Middle Assyrian kings' regnal dates, which would need to be lowered given that the unadjusted Assyrian lunar year was slightly shorter than its solar counterpart.