Bungie announced the Fortnite update 17.20 on the official Twitter channel. The patch will be released earlier than the previous updates, and the download will be available around 02:30 AM ET.
Remember, there will be different version numbers depending on the platform: PS4 Update 3.23 | PS5 update 1,000,034.
In summary: The Fortnite servers will be offline on July 20th around 02:30 AM ET (06:30 UTC). Update 17.20 is released.
As soon as the patch notes are in, we will provide them for you!