https://www.polygon.com/2017/11/30/16719594/destiny-2-servers-are-down-maintenance-curse-of-osiris

Destiny 2 servers are down tomorrow, Dec. 1, for scheduled maintenance, likely to prepare for the upcoming expansion scheduled to release on Dec. 5, Curse of Osiris.

Scheduled maintenance is expected to start at 8:00 a.m. PT and last until 2:00 p.m., and progress will be given on Twitter and at the Bungie website.