Diablo 4 Season 1 Start Date: July 21/28?

Diablo General Manager Rod Fergusson confirmed on Twitter Blizzard will be revealing more details about the premiere Diablo 4 Season this week.

Let's goooooo! Oh wait, but I'm not on it. Who'll do the 30 second dance party or bring the s'mores? Fine, be all professional and stuff… lot's of great info coming your way! https://t.co/oQPGNtZI7l
— Rod Fergusson (@RodFergusson) June 30, 2023

From past seasons, we can extrapolate the following:

Diablo seasons start on Fridays.
Blizzard usually makes announcements two weeks in advance.

When Will Diablo 4 Season 1 Start?

That said, we have two possible release dates for Season 1 — July 21 or July 28.

Source: Reddit