https://www.polygon.com/2018/8/23/17775422/destiny-2-forsaken-raid-release-date-last-wish-ahamkara-uldren

Destiny raids have typically gone live just a few days after a new expansion. However, Destiny 2: Forsaken’s raid, known as Last Wish, will not be released until a full week and a half after the expansion debuts. Bungie announced the specific date and time, and the reason for this change, in this week’s This Week at Bungie.

The new raid, which will take place in the mysterious Dreaming City, will be released on Sept. 14 at 1 p.m. EDT. Once it’s available, all players will gain the chance to take down the monsters that Bungie has promised us. Senior raid designer Joe Blackburn said that players will need more than the usual three days to prepare, and that the team at Bungie wanted to be sure that the community had an opportunity to experience the full expansion before slamming into the hardest content.