In North America, the PlayStation Store, PlayStation Home and account management options will be unavailable during the downtime, which starts at 11 a.m. ET and runs until 11 p.m. ET. In Europe, the takedown will last a bit longer, starting at 2 p.m. BST and running until 5 a.m. BST the next day.
As with all maintenance windows, PlayStation Network users can still play games online during the outage, so long as they've logged on to the network before it gets taken offline.