Edward M. Reingold – författare

The momentous task of assembling such a comprehensive and accurate collection of calendars could only have been achieved by the authors of the definitive text on calendar algorithms, Calendrical Calculations. Using the algorithms outlined in their earlier book, Professors Reingold and Dershowitz have achieved the near-impossible task of simultaneously displaying the date on thirteen different calendars over a three-hundred year period. Represented here are the Gregorian, ISO, Hebrew, Chinese, Coptic, Ethiopic, Persian, Hindu lunar, Hindu solar, and Islamic calendars; another three are easily obtained from the tables with minimal arithmetic ( J.D., R.D. and Julian). The tables also include phases of the moon, dates of solstices and equinoxes, and religious and other special holidays for all the calendars shown. Why produce a book of tables in the computer age? Because computer programs can cover only one or two calendars, have a limited range, are of dubious accuracy, are difficult for a non-expert to use, or work only on a small subset of computers. This set of beautifully-produced tables will be of use for centuries by anyone with an interest in calendars and the societies that produce them. It should also prove an invaluable reference tool for astronomers and genealogists.

An invaluable resource for working programmers, as well as a fount of useful algorithmic tools for computer scientists, astronomers, and other calendar enthusiasts, The Ultimate Edition updates and expands the previous edition to achieve more accurate results and present new calendar variants. The book now includes coverage of Unix dates, Italian time, the Akan, Icelandic, Saudi Arabian Umm al-Qura, and Babylonian calendars. There are also expanded treatments of the observational Islamic and Hebrew calendars and brief discussions of the Samaritan and Nepalese calendars. Several of the astronomical functions have been rewritten to produce more accurate results and to include calculations of moonrise and moonset. The authors frame the calendars of the world in a completely algorithmic form, allowing easy conversion among these calendars and the determination of secular and religious holidays. LISP code for all the algorithms is available in machine-readable form.