Books : reviews

Edward M. Reingold, Nachum Dershowitz.
Calendrical Calculations: the millennium edition.
CUP. 2001

This new edition of the successful calendars book is being published at the turn of the millennium and expands the treatment of the previous edition to new calendars and variants. As interest grows in the impact of seemingly arbitrary calendrical systems upon our daily lives, this book frames the calendars of the world in a completely algorithmic form. The book gives a description of twenty-five calendars and how they relate to one another: the Gregorian (current civil), ISO (International Organization for Standardization), Egyptian (and nearly identical Armenian), Julian (old civil), Coptic, Ethiopic, Islamic (Moslem), modern Persian (both astronomical and arithmetic forms), Bahá’í (both present and future forms), Hebrew (Jewish), Mayan (long count, haab, and tzolkin), Balinese Pawukon, French Revolutionary (both astronomical and arithmetic forms), Chinese (and nearly identical Japanese), old Hindu (solar and lunisolar), and modem Hindu (solar and lunisolar). Easy conversion among these calendars is a by-product of the approach, as is the determination of secular and religious holidays. Calendrical Calculations makes accurate calendrical algorithms readily available for computer use with LISP, Mathematica, and Java code for all the algorithms included on the CD, and updates are available on the Web.

This book will be a valuable resource for working programmers as well as a fount of useful algorithmic tools for computer scientists. In addition, the lay reader will find the historical setting and general calendar descriptions of great interest.

Cristian S. Calude, Jose Felix Costa, Nachum Dershowitz, Elisabete Freire, Grzegorz Rozenberg.
Unconventional Computation, UC 2009: Ponta Delgada, Azores, Portugal.
Springer. 2009


(read but not reviewed)