One of those books that comes out once every ten years. One of the most important foundational books of Greek literature and the most significant in its field. It is a literary feat that evokes awe in the reader.

Its subject matter is the calendrical systems of all peoples, from all times, of humanity. The authors of this magnificent study, assistant professors of Astrophysics at the University of Athens, offer the reader a scientific and at the same time fascinating journey through history, religion, art, science, and global culture in general.

Knowledge as the literature of our time. The narrative unfolds in two volumes totaling 850 pages. In the first volume, after introductory information on the methods of constructing calendrical systems, the calendars of the peoples of Mesopotamia, Ancient Egypt, ancient Iran, ancient Israel, China, India, Japan, Korea, pre-Columbian peoples of America, the Islamic world, Western Africa, and Ancient Greece are examined.

The information for each of the aforementioned calendars is accompanied by overviews of the history and culture of the peoples who used these calendars, calendrical tables, and photographic material.