Okay, I copied your code and ran "as is".
Start the server first and then the client, works fine. I would put into the server an output to indicate that it's waiting for the connection:
System.out.println("Waiting for connection");
Socket s=ss.accept();
System.out.println("Connection received");
Also the date object will remain at the same time as you only instantiate it once. Better would be to move that line inside the while loop