The PlayStation Network will be going down on August 18, for scheduled maintenance.
PlayStation Notwork, at least on August 18 for a few hours.
PSN will be offline for about an hour and a half on Tuesday, August 18 between 4:30am BST and 6am BST, so it shouldn't affect too many people.
You will still be able to sign in to your profile, play games and use most apps during the maintenance but you won’t be able to access Account Management, PlayStation Video, or make purchases through the store.
The Call of Duty: Black Ops III beta kicks off the next day, so that's probably your reason right there.