Abstract
Sider (2001) and Hawley (2001) argue that, in order to account for the mere possibility of change, temporal parts must be as fine-grained as possible change, and hence as fine-grained as time. However, when dealing with metaphysical possibility, the fine-grainedness of actual time and the fine-grainedness of possible change can come apart. Once this is taken into account, we see that, on certain assumptions about the actual microstructure of time, the modal arguments of Sider and Hawley lead to the problematic claim that temporal parts are more fine-grained than time. The utility of a temporal parts theory thus seems to be sensitive to metaphysically contingent facts concerning the microstructure of time