Calendar: Humanity's Epic Struggle to Determine a True and Accurate Year

Duncan, producer for ABC News and author of books on subjects ranging from medical training (Residents) to de Soto's exploration of the Southeast (Hernando de Soto), meticulously recounts the development of our Gregorian calendar, which begins on January 1, has 12 months of 28 to 31 days each and usually adds a leap day every four years. He explains how Julius Caesar's affair with Cleopatra led to the Julian calendar used in Europe until 1582; why the Venerable Bede was venerated for his work on the calendar; how the dating of Easter and other religious holidays kept a flicker of scientific investigation burning throughout the so-called Dark Ages; and why March 24 used to be New Year's Eve. This extensively researched book is more than a history of our calendar and the determination of the precise length of the year, however. It is also an absorbing essay on the cross-pollination of ideas, as the astronomical and mathematical knowledge of the classical Greeks was carried by Alexander's armies to India, from whence it returned to ignite the rebirth of learning in Europe during the Middle Ages. In well-positioned asides, Duncan explains the impact of the Indian development of our 10-digit number system on determining an accurate year, and the influence of Islamic culture (although Muslims still live by a different calendar). Duncan overwrites at times, and his work is overwhelmingly Eurocentric, with African and Native American calendar systems mentioned only in passing and Asian ones given scant attention. Nevertheless, this accomplished interdisciplinary work will appeal to all readers tyrannized by the date book. BOMC, QPB and History Book Club featured alternates; author tour. (July)