Mapping Time: The Calendar and its History (review)

Mapping Time: The Calendar and Its History. By E. G. RICHARDS. New York: Oxford University Press, 1998. Pp. xxi + 438. $16.95 (paper).

Following in the path of other academics who have taken on world historical topics, E. G. Richards, a biophysics professor at King's College, University of London, has written a general work on the calendar and its history. This approach to the topic from a nonhistorian makes the work strong as a reference work in the various types of calendars in use throughout history all over the world, but those looking for deeper historical analysis of the meaning and use of calendars are likely to be disappointed. Richards came to this topic after working on computer programs for calendar conversion, and much of the text is devoted to the mathematics and mechanics of converting dates to and from various calendars. Whereas some scientific approaches to historical issues, such as Jared Diamond's Guns, Germs and Steel have raised important points for debate and provided an illuminating narrative, Richards's work is simply encyclopedic.

That being said, the research done on the various calendars is excellent, and Dr. Richards provides a great deal of information on the types of calendars used throughout the course of world history. Mapping Time's conversational prose style helps make the discussions of the mechanics of calendar making much more readable than they otherwise could be. The first part, "The Calendar in Theory," breaks down the relationship between the use of calendars and astrology, clocks, writing, and mathematics. The religious function of timekeeping is given special weight here, and the link between the very early religions, their festivals and ceremonies, and keeping accurate track of time is central to Richards's discussion throughout the work. Calculating the date of Easter is actually given its own chapter by way of illustrating the fundamental connection between ritual and timekeeping.

Part two of Mapping Time is devoted to discussions of the calendars of the world. Each major system of timekeeping is given some attention, including the Julian and Gregorian Christian calendars, the Hindu, Islamic, Mayan, French Revolutionary, Chinese, and some proposed calendars not yet implemented. The text also makes some comparison of accuracy between each calendar system. One major theme that Richards devotes attention to is dealing with intercalated days, or leap years. Since no calendar is one hundred percent accurate, each system has had to come up with a means of adding a day or days to an occasional year. The most interesting sidenote here is the discussion of the politics of the intercalated days in Rome, which led to an increasingly inaccurate calendar and thereby to the Julian reforms and the early Christian calendar. The occasional anecdote of this sort helps break up the text and make it much more digestible for the average reader. For instance, Richards's discussion of the Julian and Gregorian calendar and the differing years of adoption leads to an amusing sidebar on the Russian Olympic team showing up twelve days late for the 1908 London Olympics.

Increasing accuracy of calendars is also discussed in some detail, though the reader may wonder why there is such a concern over making a calendar more accurate than it already is. The issue of accuracy and need highlights some of the most interesting aspects of interest to the specialized historian, although the short summaries are fine for the generally educated reader for whom the book seems to have been written.

Unfortunately, the general reader and nonmathematically minded historians may be put off by the last parts of the book, which deal with conversions from one type of calendar to another and with calculating dates. The algorithms provided in the text for calendar conversion may be useful, but reading them one after the other is simply repetitive and not terribly enlightening. The short chapter on calculating Easter is more readable and illuminating, since it is easier for the layperson to see what...