Sony announced that PSN will be briefly unavailable on Monday, April 15th due to routine maintenance.
In order to continue bringing you the best online games experience on PSN, we will perform routine maintenance beginning the morning of Monday, April 15th," a Sony Community Manager wrote on PlayStation Community website. This maintenance will start at approximately 8:00AM PT (9:00AM MT / 10:00AM CT / 11:00 AM ET) and last until around 8:00PM PT (9:00PM MT / 10:00PM CT / 11:00PM ET).”
"If you attempt to sign-in during this period, you may receive a maintenance notification when attempting to access PSN. The PlayStation Store, PlayStation Home and Account Management will not be available during the maintenance period. However, you WILL be able to access online play and apps provided that you have signed in to the Network at some point between now and the time of the maintenance. So please be sure to sign in now if you wish to access the Network during Monday’s maintenance window."