From PlayStation Universe: “The release date for the Destiny 2 Forsaken DLC is here. Ushering in a new chapter for Bungies shooter, content will go live later today on September 4. So, find out what you should dismantle before the release of Forsaken, and check out what time the fun begins.”
Source: N4G PC Destiny 2 Forsaken DLC: When Does Forsaken Come Out?