The study of time, astronomy, and calendars, has been closely intertwined in the history of Western culture and, more particularly, Jewish tradition. Jewish interest in astronomy was fostered by the Jewish calendar, which was based on the courses of the sun and the moon, whilst astronomy, in turn, led to a better understanding of how time should be reckoned. Time, Astronomy, and Calendars in the Jewish Tradition, edited by Sacha Stern and Charles Burnett, presents a wide selection of original research in this multi-disciplinary field, ranging from Antiquity to the later Middle Ages. Its variety of approaches and sub-themes reflects the relevance of astronomy and calendars to many aspects of Jewish, and more generally ancient and medieval, culture and social history. Contributors include: Jonathan Ben-Dov, Reimund Leicht, Marina Rustow, Francois de Blois, Raymond Mercier, Philipp Nothaft, Josefina Rodriguez Arribas, Ilana Wartenberg, Israel Sandman, Justine Isserles, Anne C. Kineret Sittig, Katharina Keim, and Sacha Stern

In the year 921/2, the Jewish leaders of Palestine and Babylonia disagreed on how to calculate the calendar. This led the Jews of the entire Near East to celebrate Passover and the other festivals, through two years, on different dates. The controversy was major, but it became forgotten until its late 19th-century rediscovery in the Cairo Genizah. Faulty editions of the texts, in the following decades, led to much misunderstanding about the nature, leadership, and aftermath of the controversy. In this book, Sacha Stern re-edits the texts completely, discovers many new Genizah sources, and challenges the historical consensus. This book sheds light on early medieval Rabbanite leadership and controversies, and on the processes that eventually led to the standardization of the medieval Jewish calendar.

Dates form the backbone of written history. But where do these dates come from? Many different calendars were used in the ancient world. Some of these calendars were based upon observations or calculations of regular astronomical phenomena, such as the first sighting of the new moon crescent that defined the beginning of the month in many calendars, while others incorporated schematic simplifications of these phenomena, such as the 360-day year used in early Mesopotamian administrative practices in order to simplify accounting procedures. Historians frequently use handbooks and tables for converting dates in ancient calendars into the familiar BC/AD calendar that we use today. But very few historians understand how these tables have come about, or what assumptions have been made in their construction. The seven papers in this volume provide an answer to the question what do we know about the operation of calendars in the ancient world, and just as importantly how do we know it? Topics covered include the ancient and modern history of the Egyptian 365-day calendar, astronomical and administrative calendars in ancient Mesopotamia, and the development of astronomical calendars in ancient Greece. This book will be of interest to ancient historians, historians of science, astronomers who use early astronomical records, and anyone with an interest in calendars and their development.

Calendars were at the heart of ancient culture and society and were far more than just technical, time-keeping devices. Calendars in Antiquity offers a comprehensive study of the calendars of the ancient Mediterranean and Near Eastern world, from the origins up to and including Jewish and Christian calendars in late Antiquity.

Calendars in the Making investigates the Roman and medieval origins of several calendars we are most familiar with today, including the Christian liturgical calendar, the Islamic calendar, and the week as a standard method of dating and time reckoning.

"Clock time", with all its benefits and anxieties, is often viewed as a "modern" phenomenon, but ancient Mediterranean and Near Eastern cultures also had tools for marking and measuring time within the day and wrestled with challenges of daily time management. This book brings together for the first time perspectives on the interplay between short-term timekeeping technologies and their social contexts in ancient Egypt, Babylon, Greece, and Rome. Its contributions denaturalize modern-day concepts of clocks, hours, and temporal frameworks; describe some of the timekeeping solutions used in antiquity; and illuminate the diverse factors that affected how individuals and communities structured their time.

The ancient mathematical basis of the Aramaic calendars in the Dead Sea Scrolls is analysed in this investigation. Helen R. Jacobus re-examines an Aramaic zodiac calendar with a thunder divination text (4Q318) and the calendar from the Aramaic Astronomical Book (4Q208 - 4Q209), all from Qumran. Jacobus demonstrates that 4Q318 is an ancestor of the Jewish calendar today and that it helps us to understand 4Q208 - 4Q209. She argues that these calendars were taught in antiquity as angelic knowledge described in 1 Enoch and the Book of Jubilees. The study also encompasses Babylonian, Hellenistic, Byzantine astronomy and astrology, and classical and Jewish writings. Finally, a medieval Hebrew zodiac calendar related to 4Q318 with an astrological text is published here for the first time.