 Endurantists think about what parts you have at different times, past, present or future. But perdurantists prefer to think atemporally about what parts you have, full stop (what parts you have, period). And they claim that you have you-yesterday, you-today and you-tomorrow amongst your parts. Endurantists don’t accept this atemporal way of talking about parthood, and so they find it difficult even to say what they don’t like about temporal parts.