PS3-Sense writes: "The PlayStation Network is sometimes in maintenance and this happens again soon. Unfortunately, the servers of the PlayStation Network will be offline worldwide. Next Saturday is the case, this has aka_Nero, Community Team Moderator of the Benelux, today confirmed on the official PlayStation Forums. The maintenance will last from 11:30 to 18:00* and will therefore, if you would play online one of the following games, you must wanted to play this offline only in that period."
(Note*: Thats about 1:30 AM to 7.00 AM US Time)