The launch of Diablo IV is scheduled for June 6, 2023. Alongside this, Blizzard announced Early Access for Diablo IV which will give you access for up to 4 days in advance starting on June 2, 2023.
Pre-Purchase Diablo IV
Early Access will be available to those who pre-purchase either the Digital Deluxe Edition ($89.99) or the Ultimate Edition ($99.99) of Diablo IV.