From Booklist: This diverting picture book addresses all manner of head-scratching quandaries kids will likely have about the concept of time: Why is it measured in such seemingly random units? When did keeping precise time become so important? And wait, what is time, anyway? It?s a pretty heady subject, all right, but Jenkins and Holland go a long way toward making the investigation fun without shirking any thought-provoking dilemmas. Beginning with the cycles and rhythms of the natural world, moving into early calendar-keeping and astronomy, and finishing with rigorous scientific inquiry (and even a succinct explanation of relativity), the text traverses Egyptian, Mayan, Chinese, Greek, and European history, explaining any number of little irregularities along the way. The mixed-media cut-illustration artwork oscillates between helpful illuminations of the text and inspired Monty Python?esque lunacy, as in the opening scene of top-hatted gentlemen riding winged clocks through the sky to convey time flying when you?re having fun. For kids inspired by pondering and excited by paradoxes, this book is as good an example as anything. Grades 3-5. –Ian Chipman