Keeping it to just one hour again, Sony announced that the PlayStation Network will be undergoing routine maintenance from Tuesday, August 23 at 11:15pm PT until Wednesday, August 24 at 12:15am PT. This maintenance period will affect the PlayStation 4, PlayStation 3, PlayStation Vita online store, and other services.
As always, you’ll still be able to sign in to your PSN profile, play games, and use most applications during the maintenance. However, you won’t be able to access Account Management, PlayStation Video, or the PlayStation Store.
Sony adds:

We recommend activating your PS4 as your primary console before maintenance begins so you can continue to play most games and use 3rd party services during maintenance. To activate your console, sign in to your PlayStation Network profile and select [Settings] > [PlayStation Network/Account Management] > [Activate as Your Primary PS4] > [Activate]. You only need to do this once. We strive to ensure that PlayStation Network services are available at all times, but occasionally we must take PlayStation Network offline to perform essential maintenance and implement feature enhancements. We are working hard to reduce the duration of each maintenance.

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