This book is the fruit of his lifelong interest in the field of calendars ... The complexity of the material has inspired the author to anticipate many of the difficulties of the student of the subject and to provide practical help for the necessary calculations in a clear and direct way ... This book is thus not only an aid to the mechanics of different calendars, but also a contribution to the understanding of the peoples of the western world whose calendars are so competently described.” – Nina L. Collins, Lecturer in Modern Hebrew, The University of Leeds