Seventh Biennial History of Astronomy Workshop
University of Notre Dame


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

This paper provides an introduction to the administrative 360-day calendar and the cultic astronomical-lunisolar calendar from Mesopotamia, as well as textual evidence of their utilization in archaic texts and/or texts from Ur III. Interplay between the two calendars in early astronomical-astrological texts will be shown through an analysis of tables from Enuma Anu Enlil XIV and from MUL.APIN.

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

The talk addresses three topics: the two calendars, civil and schematic, encountered in Mesopotamian astronomy and their principal variants; the evolution of intercalation practices in the Late Babylonian period culminating in their standardization early in the 5th century B.C; and a survey of the 8 progressively more accurate values for the length of the year found in cuneiform astronomical texts.

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

The aim of this paper is to review, in the spirit of this session on "Calendars and Years" at the biennial Notre Dame Workshop on the History of Astronomy, what we know about the structure of the calendar year in ancient Egypt, its length, its structure, its origin, and so on. The focus will be on the presentation of the hard evidence as it is found in the surviving sources. The history of the modern study of the ancient Egyptian year up to the present day will also be surveyed. In the history of humanity, someone somewhere sooner or later simply had to notice that 365 is the integer number of years that is closest to the true length of the solar year or year of the seasons and in addition put this number 365 into calendrical practice. The surviving historical evidence leaves no doubt that the ancient Egyptians were first. What is more, they were ahead of everyone else by two to three thousand years. The sole division of 365 days that is positively recognizable in the sources is one into 12 months of 30 days plus 5 added days. This calendrical structure was known already in antiquity as the "civil" calendar. This continuous cycle of 12 x 30 + 5 is often praised for its simplicity, as if it is a work of genius. In addition to the civil year, lunar years were also used, but their use was restricted mainly to the religious domain. These lunar years and their relation to the civil year will be discussed as well.

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

The Library of Qumran provides us with a lot of calendrical texts. Nearly all of them contain one common element: the number of 364 days within a year. Despite this common element, the concepts are not totally the same in all texts. It seems not to be appropriate to talk of the 364-days-calendar of Qumran as a unity, but a plurality of contexts and concepts can be seen. In some elements even historical developments may be recognized. For example, the oldest materials within the book of Enoch contrast its own concept with 364 days against a 360-day reckoning. But Enoch materials from 200 BCE (and earlier) and calendrical references in the book of Jubilees do not refer to priestly courses, which in a bulk of other texts from Qumran serve as a base for the weekly structure of time (as in later inscriptions in several synagogues). Some texts do have a positive reference to lunar events, while comparable elements are missing in other calendrical writings--or are declared as the mistake of those who are in error as the book of Jubilees explicitly states.

To give an overview about the material as well as a sketch of possible backgrounds for the common elements within the 364-day concepts is the topic of the contribution. It will also deal with the empirical and religious needs of Jewish groups and their astronomic-cosmological world views in the last centuries BCE.

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

The Middle Assyrian tablet KAV 218 (Astrolabe B) and its parallels, commonly known as 'The Astrolabes,' form the earliest surviving group of cuneiform astronomical texts. These works present an astronomical-calendrical theory by which the starry sky is divided into three east-west stellar paths: the northern Path of Enlil, the central Path of Anu, and southern Path of Ea. These in turn are further divided into twelve stellar sectors; one for each month of the year, thereby yielding a repertoire of 36 month-stars whose risings and settings mark the months of the year. The Babylonian national creation epic Enuma Elish teaches that it was the Babylonian King of the Gods, Marduk himself, who established this system at the time of creation. In this paper I will present findings from my long standing project studying the sources belonging to the Astrolabe group.

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

In this talk I will discuss whether the length of the month in the Late Babylonian calendar was determined by observation of the first visibility of the lunar crescent, or prediction of this event. The talk will also address whether there existed an astronomers' calendar running alongside a civil calendar in the Late Babylonian period.

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

This paper discusses the yearly cycle of a star in the Egyptian sky based on the evidence presented in various types of 'star clocks' and astronomical diagrams. The relationship between these astronomical representations and the civil calendar are explored, including the cycle of updates to the diagonal star clock tables proposed by Neugebauer and Parker.

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