We see a bunch of different things in the world and we want to describe the differences between them, so we invent distance to describe their shape and size in relation to one other, weight to describe their mass in relation to one other, and time to describe how they change in relation to one other. Is this description an illusion? In a way. But also in a way not. An inch is not real, but the space which an inch represents is real. See what I mean? Things change, that's real. But 'time' as a separate thing which makes other things change? No that's not real. It's all together, not fragmented like we think into 'time' and 'space' and such; that's just our filing cabinet of a brain's way of sorting the world.