https://support.us.playstation.com/a...tail/a_id/2185

Maintenance
[PlayStation®Network] Updated 08/20/2013
In order to continue to deliver you the best online games experience, we will be performing maintenance to upgrade the software for the PlayStation Store on Thursday, August 22. This maintenance will occur between:

Start at approximately: Thursday, August 22, 12:00 Noon PT (1:00PM MT / 2:00PM CT / 3:00PM ET)
End at approximately: Thursday, August 22, 6:30PM PT (7:30PM MT / 8:30PM CT / 9:30PM ET)
During this maintenance period, you may receive a message that states “Sony Entertainment Network is undergoing maintenance” when attempting to access the PlayStation Store or PlayStation Home.



We will update you with any changes that may occur in regards to this scheduled maintenance. If you would like to receive a notice when PSN is fully restored, be sure to follow the official PlayStation Twitter account and our support Twitter account, @AskPlayStation.