https://www.gamespot.com/articles/destiny-2-servers-down-for-maintenance-update-back/1100-6455006/

If you wanted to play Destiny 2 right now, you're out of luck for a few hours. Developer Bungie is taking the game offline to perform some Destiny 2 server maintenance on PS4, Xbox One, and PC, and it will release a new hotfix update in the process. [Update: Server maintenance has concluded, and you can start playing again. Destiny 2 update 1.0.7 (and 1.0.7.1 on PC) are now available.]

Players will no longer be able to log in from 8 AM PT / 11 AM ET / 4 PM GMT on November 16 (that's 2 AM AEST on November 17 in Australia). An hour later, anyone still playing the game will be booted to the title screen. Bungie says the maintenance will end three hours after that--at 12 PM PT / 3 PM ET / 8 PM GMT (6 AM on November 17 in Australia)--at which point hotfix 1.0.7 "is expected to be available to download and install on all platforms." However, be aware that previous Destiny 2 maintenance has sometimes gone on for longer than expected.