https://www.gamespot.com/articles/fortnite-servers-down-on-ps4-xbox-one-and-pc-updat/1100-6456530/

Following a delay, Epic Games is prepared to release the new update for Fortnite. However, that process will require a period of server downtime, which begins at 10 AM PT / 1 PM ET / 6 PM GMT on PC, PS4, and Xbox One. There's no time table for how soon it will return, but we'll keep this story updated with any developments. [Update: Servers are back online, and Fortnite's new update is now available. However, you may run into a queue when trying to play for the time being.]