- Ian Stewart:
- One of the most fascinating books I've read
all year. Takes chronology into the computer age with impressive erudition
and elan. Just finding out what the calendar rules are is usually
close to impossible: Calendrical Calculations tells you how to use them
too. A must for everyone who worries about days, months, years and
why they never quite fit.
- Martin Gardner:
- The book is a definitive account of the
world's major calendars and how to use them. It will be of interest not only
to mathematicians, but also to historians and laymen. The authors are to be
congratulated on a splendid research job.
- E. G. Richards, Nature (1 Jan 1998):
- ...this book
must surely become the standard work on calendar conversions. No historian,
chronologist or recreational mathematician should be without it.
- Antonio F. Rañada, European Journal of Physics (Mar
- ...a really attractive book, not only for specialists such as
mathematicians, astronomers or computer scientists, but also for historians or
for any person interested in the cultural aspects of science. I doubt that
such a clear exposition of the mathematical structure of the calendar rules
necessary to move from one to another of these fourteen calendars could be
found elsewhere. ...this is a splendid book, of interest to astronomers and
computer scientists, and to anyone concerned with the role of science in the
cultural evolution of mankind.
- A. A. Mullin, Computing Reviews (May 1998):
I recommend this book highly both as a software resource for students and
teachers of computer science and to general readers interested in the history
and science of the world's main calendars.
- V. J. Katz, Mathematics Reviews (July 1998):
If you are at all interested in in how we deal with time, you must have this
- F. Richard Stephenson, Astronomy Now (Aug 1998):
This book provides a comprehensive numerical treatment of a wide variety of
calendars and much originality and effort has gone into its production.
...suitably equipped readers should find this a valuable reference work.
- I. J. Lund, Amazon.com (23 Aug 1998):
Excellent source for calculations of many world calendars....
The explanation of the algorithms and descriptions of
the exact details of calculation of calendars is extremely clear and well
- A reader from USA, Amazon.com (2 Oct 1998):
...this is simply the best reference for Calendrical Calculations in the
computer age. No other book comes close in terms of completeness and
thoroughness. A must-have for anyone interested in this area of history or
- D. McCarthy, ISIS (Dec 1998):
The work is attractively produced and well written, in a crisp and lucid
style, its earnest content lightened by touches of humor and details of
history that communicate most effectively the authors' enthusiasm for and
knowledge of their subject.
...this book supplies the essential tools to enable
us to proceed cogently and efficiently toward correlation of all these
derivative calendrical systems, and Dershowitz and Reingold are to be
congratulated on making strides toward this goal.
- email@example.com from California, Amazon.com (18 Jan 1999):
Just what I needed. In the course of building a 10,000 year clock I needed to
know a lot of obscure details about various calendar systems. Calendrical
Calculations not only answered all my questions, but it also introduced me to
a lot of interesting information that I never would have thought to ask
about. It is one of those rare books that is both an authoritative reference
source and a fun read.
- R. Poole, British Journal for the History of Science (Mar 1999):
What a wizard wheeze! ...Dershowitz and Reingold...have devoted a large part
of their joint lives to a task which anyone in their right mind will be glad
someone else did. ...As the millennium approaches, books purporting to explain
the calendar are appearing like cactus flowers after a storm, full of
secondhand errors, third-order simplifications, and outright myths.
Dershowitz and Reingold, by contrast, have worked at source and confronted
every difficulty. Their book can be recommended as a pithy and reliable
distillation of all the world's main calendars. As a bare work of reference,
it leads the market.
- A reader from Munich, Germany, Amazon.com (28 Apr 1999):
...highly readable and reliable description of many calendars. The book
explains the structure of 14 calendars, and gives easily comprehensible
formulae for the conversion of a date in any of these calendars into a day
count, and back to the calendar date. It also includes many holidays for these
calendars. ...the focus is on a lucid, correct, and complete exposition of
their functional principles. Extensive bibliographic references are given to
the primary sources for each calendar. A highlight is the complete
specification of several calendars depending on fairly precise timings of
astronomical phenomena (Chinese calendar and some Hindu religious calendars).
...The formulae are designed so that it is easy to incorporate them into code
written in the programming language of your choice. This use is further
supported by a set of test dates in an appendix. Another appendix lists an
example implementation of all the formulae, in the programming language Common
Lisp. This code (intended for personal use) can also be downloaded from the
internet. But this book is much more than a collection of programming recipes
for many calendars -- it makes you understand the structure of those
calendars. Ambitious readers can even find the data and the methods to
construct their own calendrical formulae. This book is a must for everybody
wanting reliable and highly readable information on the functional principles
of the world's calendars.
- William Wynne Willson, The Mathematical Gazette (Mar 1999):
This is a fascinating book to dip into, as well as being a powerful reference
work assembling a rich collection of historical, astronomical and
computational `calendar' facts. If you have funds set aside for coping with
the millennium bug why not spend a little of them on a copy?
- Giuseppe Gatto, Calendrier et informatique (Jul
...une œuvre considérable sur les calculs calendaires.