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.

With time-related anecdotes, quotes and trivia, this is an essential handbook for anyone fascinated by the fourth dimension.

Travel through time with the maestros as they explore the amazing history of timekeeping! Did you know that there is more than one calendar? While the most commonly used calendar was on the year 2000, the Jewish calendar said it was the year 5760, while the Muslim calendar said 1420 and the Chinese calendar said 4698. Why do these differences exist? How did ancient civilizations keep track of time? When and how were clocks first invented? Find answers to all these questions and more in this incredible trip through history.

What is time? When did we first use it? Does it always work? How do animals tell time? A fun and fascinating look at time from the first calendars and clocks to the digital watches and precise time-keeping methods of today.

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.

Rather than being an isolated, primitive body of knowledge the Jewish calendar tradition of 364 days constituted an integral part of the astronomical science of the ancient world. This tradition—attested in the Dead Sea Scrolls and in the Pseudepigrapha—stands out as a coherent, novel synthesis, representing the Jewish authors’ apocalyptic worldview. The calendar is studied here both “from within”—analyzing its textual manifestations —and “from without”—via a comparison with ancient Mesopotamian astronomy. This analysis reveals that the calendrical realm constituted a significant case of inter-cultural borrowing, pertinent to similar such cases in ancient literature. Special attention is given to the “Book of Astronomy” (1 Enoch 72-82) and a variety of calendrical and liturgical texts from Qumran.

#1 INTERNATIONAL BESTSELLER AN ADAM SAVAGE BOOK CLUB PICK The book-length answer to anyone who ever put their hand up in math class and asked, “When am I ever going to use this in the real world?” “Fun, informative, and relentlessly entertaining, Humble Pi is a charming and very readable guide to some of humanity's all-time greatest miscalculations—that also gives you permission to feel a little better about some of your own mistakes.” —Ryan North, author of How to Invent Everything Our whole world is built on math, from the code running a website to the equations enabling the design of skyscrapers and bridges. Most of the time this math works quietly behind the scenes . . . until it doesn’t. All sorts of seemingly innocuous mathematical mistakes can have significant consequences. Math is easy to ignore until a misplaced decimal point upends the stock market, a unit conversion error causes a plane to crash, or someone divides by zero and stalls a battleship in the middle of the ocean. Exploring and explaining a litany of glitches, near misses, and mathematical mishaps involving the internet, big data, elections, street signs, lotteries, the Roman Empire, and an Olympic team, Matt Parker uncovers the bizarre ways math trips us up, and what this reveals about its essential place in our world. Getting it wrong has never been more fun.