Book excerpt: Time has always been the great Given, a fact of existence which cannot be denied or wished away; but the character of lived time is changing dramatically. Medical advances extend our longevity, while digital devices compress time into ever briefer units. We can now exist in several time-zones simultaneously, but we suffer from endemic shortages of time. We are working longer hours and blurring the distinctions between labour and leisure. For many, in an inversion of the old adage, time has become more valuable than money. In this look at life's most ineffable element, spanning fields from biology and culture to psychoanalysis and neuroscience, Eva Hoffman asks: are we coming to the end of time as we know it?