Sold a car capital gain..buyer hasn't picked it up

[Samantha Klein]

Hello, I am looking for a CPA that could tell me when I should report the capital gain I am making... I sold a 1969 Charger on July 18, the buyer notified me he can't get the car until Oct and the title has not been signed over, I will be making a capital gain of 20k on the car, do I put down July 18 as the sale date or when he actually picks it up?  The buyer already paid me.