This is a dense and well-argued monograph, a magnum opus presenting Stern's work in the recent decade on calendars and politics in the ancient world. In his illuminating introduction Stern declares his credo: “The calendar should not be confined, as it sometimes is, to the history of science or to a marginal aspect of the history of religions. It firmly belongs to the core of social history” (2). Stern has already performed a similar task with regard to the Jewish calendar in his 2001 monograph Calendar and Community. The present book does not focus on Jewish calendars, and its explicit treatment of them seeks their integration into the larger dynamics of calendars in the ancient world. Despite all that, students of Judaism will benefit from the chapters dedicated to Jewish issues: mainly the 364-day Qumranic year (193–203, 359–379), the rabbinic lunar calendar, and the new moon procedure (331–352).

The main thrust of the book is the clear historical process traced by Stern: Calendars of the ancient world shifted from a predominance of lunar calendars under the great empires of the first millennium BCE to an overwhelming dominance of fixed calendars—mostly solar—under the Roman Empire in late antiquity. The calendar was a means in the hands of empires for gaining stability in time reckoning, enhancing efficiency of administration, and boosting international trade. The story is thus a political one. The lunar calendar—as developed in Assyria and Babylonia and particularly under Achaemenid rule—brought predictability to the ancient Near East until the days of the Seleucid Empire. In contrast, the Egyptian civil calendar exerted significant influence in the last centuries BCE in various ways, until it gained world dominance with Caesar's reform in 46 BCE, later amplified by Augustus. Part 1 of the book traces this historical development, while part 2 isolates moments along it that defy its simplistic application, and thus require explanation by means of a more complicated theory. In this latter part Stern formulates his own intricate version of a postcolonial theory, explaining calendar divergences in Roman provinces, from Judea to Gaul, as an intricate interplay of subservience and dissidence.

Following an illuminating methodological introduction, chapter 1 discusses Greek calendars, with the message that Greeks did not consider a lunar calendar flawed if it was out of sync with the actual phases of the moon. In this chapter Stern delves into the notorious Pritchett-Meritt debate about Athenian calendars, leaning more closely to the former. Chapter 2 covers Mesopotamian lunar calendars, largely in the first millenium BCE, describing the transformation of these calendars from observational decrees to precalculated months and years, with a novel evaluation of the development of the nineteen-year cycle. Detailed analysis of the dates in Babylonian astronomical diaries indicates that they were decided by prediction rather than by observation earlier than usually assumed, while on the other hand intercalation and new moon procedures were occasionally decided by decree (see however J. M. Steele, in Oxford Handbook for Cuneiform Culture [Oxford: Oxford University Press, 2011], 481). Chapter 3 discusses the Egyptian calendar, with a sober evaluation of such documents as P.Ebers, P.Carlsberg 9, and the Canopus decree, yielding a novel (and in my eyes more feasible) understanding of the lunar calendar in Ancient Egypt. Chapter 4 then discusses trajectories of the Egyptian calendar: the Persian “Zoroastrian” calendar (whose conception Stern places already in Achaemenid times) and the Jewish “Qumranic” 364-day year (which Stern conceives, unconvincingly in my opinion, as a development of the Egyptian year under Ptolemaic rule). Chapter 5 then covers the Roman calendar, from its earliest (pre-)Republican roots. Special attention is given to the conception of the Julian year and to its robust enforcement throughout the empire. Part 1 thus ends with an overall dominance of the Julian calendar throughout the empire.

Part 2 introduces caveats to this sweeping conclusion. Chapter 5 traces the elaborate and by no means equivocal reception of the Julian calendar in the East. Post-Seleucid states retained a lunar calendar. Even those who announced their adherence to the Julian year retained distinct parts of their traditional systems intact. Here follows a lucid analysis of the famous decree, which introduced the Roman year in the province of Asia in 8 CE, declaring the birthday of Augustus as New Year's Day. The main achievement of this chapter is a rare concentration of information on the calendars of the East in late antiquity, information that was hard to reach beforehand.

The rabbinic calendar, as reported in tannaitic sources, must be understood against this background too, as explained in chapter 6. Stern explicates anew the rabbinic New Moon procedure, based on the political conditions of the Roman East. He astutely estimates the power of the rabbinic authorities vis-à-vis that of nonrabbinic circles and Diaspora Jews (343). The rabbinic calendar is explained in light of other dissident lunar calendars throughout the empire: in the south of Italy and in Roman Gaul (with a masterful evaluation of the Coligny calendar). Finally, chapter 7 examines whether the calendar may be connected with sectarianism, as is often done in research. Stern objects to the common depiction of the Jewish 364-day year as a sectarian device, and then moves to explain early Christian calendars, with special emphasis on the Computus tables. He suggests, as in his 2001 monograph, that the fixing of the rabbinic calendar was influenced by the contemporary fixing of Christian calendars as part of that effort.

This is not a Handbuch der Chronologie, like Ginzel's 1911 book, which is replete with comparative tables and astronomical formulae. Rather, it is a theoretical historiographic monograph that uses calendrical data as its subject matter. Stern succeeded in presenting both the necessary technical data (mostly in the footnotes) and an articulate, at times even attractive flow of argument. To that end he displays breathtaking mastery of ancient literature, from Classics and rabbinics—his alma mater—to Coptic, Syriac, Persian, archaic Greek, Assyrian and many other traditions.

Stern is fond of disproving earlier discussions of astronomical objects or inventories, to which earlier authors imbued exaggerated scientific abilities. This is a great asset to the study of calendars, which for a long time lacked writers with a sound historical judgment alongside their technical skills. Let us hope the book attracts more competent historians to this demanding yet promising field.

The present review is hardly sufficient for mentioning points of criticism and disagreement with Stern's magnum opus. Naturally there are quite a few of them, but they pale in comparison with Stern's major achievements in this important monograph.