From the ice-age recordings of moon cycles and the earliest calendars, to modern wristwatches and quantum clocks, time and its effects have always enthralled mankind. We've spent centuries developing new ways of measuring time, describing it and quantifying it, and such methods have given rise to some of the most technically and aesthetically beautiful devices ever invented. This book is a tribute to timekeeping in its many forms and takes in the most significant creations as well as countless time trivia - peppered with time-related anecdotes and quotes, this really is an essential handbook for anyone fascinated by the fourth dimension.