https://www.gamespot.com/articles/fortnite-servers-going-down-before-new-ps4-xbox-on/1100-6457419/

You won't have to wait much longer for Fortnite's delayed v3.3 update. It was originally due out on March 14, but developer Epic discovered an issue and had to delay it. Thankfully, the wait won't be long, as the patch is now scheduled to launch in the morning on March 15.

Server downtime related to the rollout will begin tomorrow at 5 AM ET / 2 AM PT, presumably on all platforms: Xbox One, PS4, and PC.