Is time real? …In one sense, it’s a silly question. The “reality” of something is only an interesting issue if its a well-defined concept whose actual existence is in question, like Bigfoot or supersymmetry. For concepts like “time,” which are unambiguously part of a useful vocabulary we have for describing the world, talking about “reality” is just a bit of harmless gassing. They may be emergent or fundamental, but they’re definitely there.

Sean Carroll