The Day Unit in Antiquity and the Middle Ages (Research Group Conference)

Sun, 10/06/2018 to Mon, 11/06/2018



Jonathan Ben Dov (University of Haifa)
Sacha Stern (University College London)


The objective of this conference is to investigate how the time unit ‘day’ was structured, measured, divided, perceived, and experienced in ancient and medieval societies.

Conference speakers include experts on the history of time reckoning from various fields such as: Assyriology, Egyptology, Classics, Mathematics, Astronomy, History of Science and the History of scientific instruments. In addition, the conceptions of the day among Jews, Muslims and Christians will be addressed.

This conference will provide novel investigations into various aspects of time such as:

- The origins and history of the division of the day into smaller time units, of which surprisingly little is known. Consideration will also be given, later in history, to the introduction and use of fractions of the hour; the distinction between seasonal and equinoctial hours. In addition, the beginning and ending of the day in various traditions will be considered.

- The impact of the division of the day on the history and development of various legal systems where the temporal structure of the day plays a significant part, e.g. Roman law, rabbinic halakhah, and monastic rules. 

- The technology of time measurement, its development and its practical use. This includes sundials, water clocks, sand clocks, star clocks, and the onset of the use of mechanical clocks. An assessment must be made of the impact of technology on the division of the day, on the conceptualization and cognition of time, as well as on the practical organization of social life.

- The definition of the day in astronomical theories vis-à-vis its application in real life. 


Program >



Jonathan Ben-Dov, University of Haifa
Francois de Blois, University College London
Gerd Grasshoff, Humboldt-Universität, Berlin
Wayne Horowitz, The Hebrew University
Sarit Kattan Gribetz, Fordham University
Tzvi Langermann, Bar-Ilan University
Mathieu Ossendrijver, Humboldt University
Sofie Remijsen, University of Amsterdam
Barbara Sattler, University of St. Andrews
John Steele, Brown University
Sacha Stern, University College London
Sarah Symons, McMaster University
Anja Wolkenhauer, University of Tübingen
Ido Yavetz, Tel Aviv University
Israel Yuval, The Hebrew University