Each time I load GT5 I get a message that says "The date and tie are not set correctly. Please check date and time settings." Does GT5 have separate settings or does it operate from the PS3 settings?
I believe this is to do with the combination of your PS3 timezone setting and the DST settings under the relevant PS3 menu option. I had to alter these two (although the time itself on the PS3 was not altered) before the message stopped appearing when loading GT5.