Babylonian Calendar Adoption

Judeans in Babylonia began adopting Babylonian month names. These developed into the Jewish names Nisan, Iyar, Sivan, Tammuz, Av, Elul, Tishrei, Kislev, Tevet, Shevat and Adar.

BM 77824 Babylonian Calendar Tablet. A cuneiform tablet from Babylonia preserving the traditional Babylonian month system and its astronomical associations. Its month names closely correspond to the later Jewish names, including Nisanu, Tashritu, Kislimu, Tebetu, Shabatu, and Adaru.