Personally, I can also recommend Philip Turetzky's Time for those interested in the question "What is Time?" from a philosophical (rather than a physical) POV.

Personally, I can also recommend Philip Turetzky's Time for those interested in the question "What is Time?" from a philosophical (rather than a physical) POV. The book is a survey of thinking about Time from the ancient Greeks through the 20th century. It is not light reading, but no philosophy PhD is needed if you read it carefully.