How did the Jewish calendar evolve from a state of regional and sectarian diversity into the unified, normative rabbinic system used today? Sacha Stern, a scholar of Jewish history and antiquity, examines the transition of time-reckoning practices between the 2nd century BCE and the 10th century CE. By synthesizing a vast array of literary, epigraphic, and documentary evidence from Jewish, Graeco-Roman, and Christian sources, Stern argues that the standardization of the calendar was a critical mechanism in the consolidation of Jewish identity during late antiquity and the early medieval period.

Scholars and historians recognize this work as a foundational text for understanding the intersection of chronology and communal identity in early Judaism. Readers frequently note the academic rigor and the breadth of primary sources utilized, making it a standard reference for those studying ancient and medieval Jewish history.