Seventh Biennial History of Astronomy Workshop
University of Notre Dame
July 7-10, 2005

Calendars and Years session
Organizers: John Steele (University of Durham) and Henry Zee (CAENO Foundation)

The session looks at the various lengths of the year found in the calendars and astronomies of ancient Egypt and Mesopotamia, including the 365-day Egyptian year, the 360-day and 364-day years of Mesopotamia and the length of the solar year in late Babylonian astronomy. Much of this is common knowledge, but the basis for this knowledge is often obscure. The origin of the various calendars and years, their period of use and the empirical foundation of our understanding are not widely known. For example, everyone recognizes the 365-day year used by Ptolemy originated in Egypt, but what is the evidence for its use in Egypt, and how far back can the 365-day year be traced in Egyptian history? The papers will review what is known about year lengths in the ancient world (with a particular focus on the sources in which they are attested) along with new research and ideas about how Egyptians and Mesopotamians managed their day-count. This session is sponsored by the CAENO Foundation.

12:30 pm to 2:30 pm: Calendars and Years, Part 1

Lis Brack-Bernsen (Regensburg University), "The 360 Day Year in Mesopotamia"

Wayne Horowitz (Hebrew University), "The Astrolabes: Astronomy, Theology, and Chronology"

John Britton (Independent Scholar), "Calendars and Year-lengths in Mesopotamian Astronomical Practice"

John Steele (University of Durham), "The Length of the Month in Babylonia during the Late Babylonian Period"

2:30 pm to 3:00 pm: Poster Viewing and Break

3:00 pm to 4:30 pm: Calendars and Years, Part 2

Leo Depuydt (Brown University), "The Calendar Year in Ancient Egypt"

Sarah Symons (University of Leicester), "A Star's Year: The Annual Cycle in the Ancient Egyptian Sky"

Uwe Glessmer (University of Hamburg), "Knowledge of Calendars through the Library of Qumran"

Seventh Biennial History of Astronomy Workshop: Complete Program-