Eastern Standard Time - S4-E18
Plot hole: When Jen introduces Joey to her father in his office, she calls her "Joey Potter from Capeside". But later when they are at dinner, Jen's father suddenly refers to Joey as "Josephine" which seems strange as he wasn't told that was her legal name, and only those who know her well would know that. Joey is not necessarily a nickname only for Josephine, so it wasn't just a logical deduction.
Answer: It's the same apartment Joey had in NYC. Comparing it to the beginning of the Finale; you can tell it's exactly the same location, furnishings, Plasma TV etc. Apparently Chris was only living with her at HER apartment, and now Pacey has taken his place at the end. I guess this implies Pacey successfully started his own restaurant business in NYC as he had dreamed, to be with Joey.