"...valuable reading for biological or medical scientists and many practitioners. As a first in its field, the volume is sure to become a classic." (Quarterly Review of Biology, March-May 2005)

"...a timely snapshot of the molecular mechanisms of biological timekeeping as we understand it today." (Genes, Brain and Behavior, March 2005)

"…better than a good book…The Alvarez chapter alone justifies its purchase, and several other excellent chapters are also quite useful." (Clinical Chemistry, January 2005)

“…presents a comprehensive account of the current state of chronobiology, delivering a ready resource for students and practitioners.” (Bio World (Germany), Vol.9, No.5 2004)

"…few other books on this subject are available. The material is on interest event to those not in the area." (Doody's Health Services)