https://www.gamespot.com/articles/destiny-2-servers-down-today-for-scheduled-mainten/1100-6453265/

Destiny 2's servers will go offline today for four hours as part of scheduled maintenance. The process will begin at 7 AM PT/3 PM BST/12 AM AEST, when players will no longer be able to log into Destiny 2 or the first Destiny.

Those that are already in the game will be removed an hour later at 8 AM PT/ 4 PM BST/ 1 AM AEST. The server maintenance is expected to end at 11 AM PT/7PM BST/4 AM AEST. The downtime comes ahead of the first wave of new content for Destiny 2, which includes a refresh of the Nightfall, the Flashpoint on Nessus, the arrival of Xur, and a new Raid.