I think it is understandable. The time you get from sqlplus and the time you get from the server(which oracle database resides on) are the same,but the time you get from sqlplus and the time you get from the client(oracle client,which is on another server) are not necessarily the same. In order to have the same time, you have to set the time on your client the same as the time on your oracle server. Correct me if I am wrong.