What is time? St Augustine famously claimed that he knew the answer as long as no one asked him for it, but as soon as he tried to explain it he no longer knew. Part of the problem is the intricate nature of the question. Every individual will approach the question 'what is time?' from a different perspective. We find ourselves asking whether time is linear or cyclic, whether it is endless, whether it is possible to travel in time, how the experience of the flow of time arises, how our own internal clocks are regulated and how our language captures the temporality of our existence. In this volume eight eminent researchers explore how investigations in their respective fields impinge on questions about the nature of time. These fields encompass the entire range from the arts and humanities to the natural sciences, mirroring the truly interdisciplinary nature of the subject.